S-3ASR

S-3ASR 1 d149032ds3asr.htm S-3ASR S-3ASR

As filed with the Securities and Exchange Commission on June 18, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ONEOK, Inc.

(Exact name of registrant as specified in its charter)

Oklahoma

73-1520922

(State or other jurisdiction of

incorporation or organization)

(I.R.S. employer

identification number)

100 West Fifth Street

Tulsa, Oklahoma 74103

(918) 588-7000

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Lyndon C. Taylor

Executive Vice President, Chief Legal Officer

ONEOK, Inc.

100 West Fifth Street

Tulsa, Oklahoma 74103

(918) 588-7000

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copies to:

Sarah M. Rechter

Brandon M. Watson

ONEOK, Inc.

100 West Fifth Street

Tulsa, Oklahoma 74103

(918) 588-7000

David J. Miller

Samuel D. Rettew

Latham & Watkins LLP

300 Colorado Street, Suite 2400

Austin, Texas 78701

(737) 910-7300

Jordan B. Edwards

Thomas J. Hutchison

GableGotwals

110 N. Elgin Avenue, Suite 200

Tulsa, Oklahoma 74120

(918) 595-4800

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement.

If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ☒

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☒

If this form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.


(Check one):

Large Accelerated filer	☒	Accelerated filer	☐

Non-accelerated filer	☐ (Do not check if a smaller reporting company)	Smaller reporting company	☐

Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

SUBSIDIARY GUARANTOR REGISTRANTS

The following are additional registrants that may guarantee the debt securities registered hereby:



Exact Name of Registrant as Specified in its Charter (1)	State of Other Jurisdiction of Incorporation or Organization	I.R.S. Employer Identification No.
ONEOK Partners, L.P.	Delaware	93-1120873
ONEOK Partners Intermediate Limited Partnership	Delaware	93-1120695
Magellan Midstream Partners, L.P.	Delaware	73-1599053
Elk Merger Sub II, L.L.C. (f/k/a EnLink Midstream, LLC)	Delaware	33-3042738
EnLink Midstream Partners, LP	Delaware	16-1616605

(1)	The address, including zip code, and telephone number, including area code, of each guarantor registrant’s principal executive office is 100 West Fifth Street, Tulsa, Oklahoma 74103, (918) 588-7000.

LOGO

Debt Securities, Common Stock, Stock Purchase Contracts,

Stock Purchase Contract Units, Preferred Stock, Depositary Shares, and Warrants

Guarantee of Debt Securities of ONEOK, Inc. by ONEOK Partners, L.P., ONEOK

Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., Elk Merger Sub II, L.L.C. (f/k/a EnLink Midstream, LLC) and EnLink Midstream Partners, LP

We may offer and sell, from time to time in one or more issuances, (1) one or more series of debt securities, which may be senior or subordinated notes or debentures, or other senior or subordinated evidences of indebtedness, which may be fully and unconditionally guaranteed by ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., Elk Merger Sub II, L.L.C. (f/k/a EnLink Midstream, LLC) and EnLink Midstream Partners, LP and which may include terms permitting or requiring holders to convert or exchange their debt securities for common stock, preferred stock or other securities, (2) shares of our common stock, (3) stock purchase contracts, (4) stock purchase contract units that consist of (a) a stock purchase contract and (b) senior or subordinated debt securities, or preferred stock, U.S. Treasury securities or other debt obligations of third parties, that may be used to secure the holders’ obligations under a purchase contract, (5) shares of our preferred stock, which may include terms permitting or requiring holders to convert or exchange their preferred stock for common stock or other securities, (6) depositary shares, or (7) warrants.

We will provide you with the specific terms of the particular securities being offered in supplements to this prospectus. Any prospectus supplement may also add, update, or change information contained in this prospectus. You should read this prospectus and each related prospectus supplement carefully before you make an investment decision. This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.

Our common stock, par value $0.01 per share, is listed on the New York Stock Exchange under the symbol “OKE.”

Investing in these securities involves certain risks. Please read “Risk Factors” on page 6 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this Prospectus is June 18, 2026.

TABLE OF CONTENTS


	Page
ABOUT THIS PROSPECTUS		1
WHERE YOU CAN FIND MORE INFORMATION		1
INCORPORATION BY REFERENCE		2
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS		2
ABOUT ONEOK		5
RISK FACTORS		6
USE OF PROCEEDS		6
DESCRIPTION OF DEBT SECURITIES		6
DESCRIPTION OF GUARANTEE OF DEBT SECURITIES		18
DESCRIPTION OF CAPITAL STOCK		19
DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE CONTRACT UNITS		24
DESCRIPTION OF DEPOSITARY SHARES		24
DESCRIPTION OF WARRANTS		26
PLAN OF DISTRIBUTION		27
LEGAL MATTERS		27
EXPERTS		27

ABOUT THIS PROSPECTUS

The information contained in this prospectus is not complete and may be changed. We have not authorized anyone else to provide you with information other than the information provided in or incorporated by reference in this prospectus, any prospectus supplement, or documents to which we otherwise refer you. We are not making an offer of any securities in any jurisdiction where the offer is not permitted. You should not assume that the information in this prospectus, any prospectus supplement or any document incorporated by reference is accurate as of any date other than the date of the document in which such information is contained or such other date referred to in such document, regardless of the time of any sale or issuance of a security.

This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission, or the SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may sell different types of securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering and the securities offered by us in that offering. The prospectus supplement may also add, update or change information in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the headings “Where You Can Find More Information” and “Incorporation by Reference.”

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by reference to the actual documents. Copies of some of the documents referred to herein have been filed or will be filed or incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below in the section entitled “Where You Can Find More Information.”

Unless we otherwise indicate or unless the context requires, all references in this prospectus to:

•

“ONEOK,” “we,” “our,” “us” or similar references mean ONEOK, Inc. and its subsidiaries, predecessors and acquired businesses;

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“common stock” mean our common stock, par value $0.01 per share;

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“preferred stock” means our preferred stock, par value $0.01 per share; and

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“securities” mean the debt securities, common stock, stock purchase contracts, stock purchase contract units, preferred stock, depositary shares and warrants described in this prospectus.

WHERE YOU CAN FIND MORE INFORMATION

We have filed a registration statement on Form S-3 with the SEC under the Securities Act of 1933, as amended, or the Securities Act, that registers the securities offered by this prospectus. The registration statement, including the attached exhibits, contains additional relevant information about us. The rules and regulations of the SEC allow us to omit some information included in the registration statement from this prospectus.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains a website that contains information we file electronically, which you can access over the Internet at www.sec.gov. Our common stock is listed on the New York Stock Exchange (NYSE: OKE). General information about us, including our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and amendments to those reports, is available free of charge through our website at www.oneok.com as soon as reasonably practicable after we electronically file them with, or furnish them to, the SEC. Information on, or accessible through, our website is not incorporated into this prospectus or our other securities filings and is not a part of these filings.

INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” the information we have filed with the SEC. This means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is considered to be part of this prospectus, and information that we file later with the SEC will automatically update and supersede the previously filed information. Our website is www.oneok.com. Information contained on our website is not part of this prospectus, and the inclusion of our website address in this prospectus is an inactive textual reference.

The documents listed below and any future filings made by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, other than any portions of the respective filings that were furnished, pursuant to Item 2.02 or Item 7.01 of Current Reports on Form 8-K (including exhibits related thereto) or other applicable SEC rules, rather than filed, prior to the termination of the offerings under this prospectus are incorporated by reference in this prospectus:

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Annual Report on Form 10-K (File No. 001-13643) for the year ended December 31, 2025, filed on February 24, 2026;

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Quarterly Report on Form 10-Q for the period ended March 31, 2026, filed on April 29, 2026;

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Current Reports on Form 8-K (File No. 001-13643) filed on January 26, 2026 (Items 5.02 and 9.01), March 25, 2026 (Items 5.02 and 9.01) and May 21, 2026 (Item 5.07); and

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the description of our common stock contained in our Form 8-A registration statement filed with the SEC on November 21, 1997, including any amendment or report filed for the purpose of updating that description.

You may request a copy of these filings (other than an exhibit to the filings unless we have specifically incorporated that exhibit by reference into the filing), at no cost, by writing or telephoning us at the following address:

ONEOK, Inc.

100 West Fifth Street

Tulsa, Oklahoma 74103

Attention: Corporate Secretary

Telephone: (918) 588-7000

We have not authorized anyone to provide you with information other than the information contained or incorporated by reference in this prospectus or in any prospectus supplement. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell, or soliciting an offer to buy, securities in any jurisdiction where the offer and sale is not permitted. You should assume that the information appearing or incorporated by reference in this prospectus, the applicable prospectus supplement or any applicable pricing supplement is accurate only as of the date of the documents containing the information, regardless of the time of its delivery or of any sale of our securities. Our business, financial condition, results of operations and prospects may have changed since those dates.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Some of the statements contained in, or incorporated by reference into, this prospectus are forward-looking statements as defined under federal securities laws. The forward-looking statements relate to our anticipated financial performance, liquidity, management’s plans, expectations and objectives for our future capital projects and other future operations, our business prospects, the outcome of regulatory and legal proceedings, market conditions, potential or pending strategic transactions, the timing thereof and our ability to achieve the intended

and projected operational, financial and strategic benefits from any such transactions, and other matters. We make these forward-looking statements in reliance on the safe harbor protections provided under federal securities legislation and other applicable laws. The following discussion is intended to identify important factors that could cause future outcomes to differ materially from those set forth in the forward-looking statements.

Forward-looking statements and other statements contained in, or incorporated by reference into, this prospectus regarding our environmental, social and other sustainability targets, plans and goals are not an indication that these statements are required to be disclosed in our filings with the SEC, or that we will continue to make similar statements in the same extent or manner in future filings. In addition, historical, current and forward-looking environmental, social and sustainability-related statements may be based on standards and processes for measuring progress that are still developing and that continue to evolve, and assumptions that are subject to change in the future.

Forward-looking statements include the items identified in the preceding paragraphs, the information concerning possible or assumed future results of our operations and other statements contained in, or incorporated by reference into, this prospectus identified by words such as “anticipates,” “believes,” “continues,” “could,” “estimates,” “expects,” “forecasts,” “goal,” “guidance,” “intends,” “may,” “might,” “outlook,” “plans,” “potential,” “projects,” “scheduled,” “should,” “target,” “will,” “would,” and other words and terms of similar meaning.

One should not place undue reliance on forward-looking statements. Known and unknown risks, uncertainties and other factors may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by forward-looking statements. Those factors may affect our operations, markets, products, services and prices. In addition to any assumptions and other factors referred to specifically in connection with the forward-looking statements, factors that could cause our actual results to differ materially from those contemplated in any forward-looking statement include, among others, the following:

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the impact on drilling and production by factors beyond our control, including the demand for natural gas, natural gas liquids (“NGLs”), the output from crude oil refineries, including products such as gasoline, diesel fuel, aviation fuel, kerosene and heating oil (collectively “Refined Products”), and crude oil; producers’ desire and ability to drill and obtain necessary permits; regulatory compliance; reserve performance; and capacity constraints and/or shut downs on the pipelines that transport crude oil, natural gas, NGLs, and Refined Products from producing areas and our facilities;

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the impact of unfavorable economic and market conditions, inflationary pressures, which may increase our capital expenditures and operating costs, raise the cost of capital or depress economic growth;

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the economic or other impact of announced or future tariffs, including inflationary impacts;

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the impact of the volatility of natural gas, NGL, Refined Products and crude oil prices on our earnings and cash flows, which is impacted by a variety of factors beyond our control, including international terrorism and conflicts and geopolitical instability (including instability in the Middle East and Venezuela);

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the impact of reduced volatility in energy prices or new government regulations that could discourage our storage customers from holding positions in Refined Products, crude oil and natural gas;

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our dependence on producers, gathering systems, refineries and pipelines owned and operated by others and the impact of any closures, interruptions or reduced activity levels at these facilities;

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the impact of scrutiny and conflicting stakeholder expectations regarding environmental, social and governance issues, including climate change, and risks associated with the physical and financial impacts of climate change;

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risks associated with operational hazards and unforeseen interruptions at our operations;

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the inability of insurance proceeds to cover all liabilities or incurred costs and losses, or lost earnings, resulting from a loss;

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the risk of increased costs for insurance premiums or less favorable coverage;

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demand for our services and products in the proximity of our facilities;

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risks associated with our ability to hedge against commodity price risks or interest rate risks;

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a breach of information security, including a cybersecurity attack, or failure of one or more key information technology or operational systems, and terrorist attacks, including cyber sabotage;

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exposure to construction risk and supply risks if adequate natural gas, NGL, Refined Products and crude oil supply is unavailable upon completion of facilities;

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the accuracy of estimates of hydrocarbon reserves, which could result in lower than anticipated volumes;

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our lack of ownership over all of the land on which our property is located and certain of our facilities and equipment;

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the impact of changes in estimation, type of commodity and other factors on our measurement adjustments;

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excess capacity on our pipelines, processing, fractionation, terminal and storage assets;

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risks associated with the period of time our assets have been in service;

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our partial reliance on cash distributions from our unconsolidated affiliates on our operating cash flows;

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our ability to cause our joint ventures to take or not take certain actions unless some or all of our joint-venture participants agree;

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our reliance on others to construct and/or operate certain joint-venture assets and to provide other services;

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our ability to use net operating losses and certain tax attributes;

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increased regulation of exploration and production activities, including hydraulic fracturing, well setbacks and disposal of wastewater;

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impacts of regulatory oversight and potential penalties on our business;

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risks associated with the rate regulation, challenges or changes, which may reduce the amount of cash we generate;

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the impact of our gas liquids blending activities, which subject us to federal regulations that govern renewable fuel requirements in the U.S.;

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incurrence of significant costs to comply with the regulation of greenhouse gas emissions;

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the impact of federal and state laws and regulations relating to the protection of the environment, public health and safety on our operations, as well as increased litigation and activism challenging oil and gas development as well as changes to and/or increased penalties from the enforcement of laws, regulations and policies;

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the impact of unforeseen changes in interest rates, debt and equity markets and other external factors over which we have no control;

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actions by rating agencies concerning our credit;

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our indebtedness and guarantee obligations could cause adverse consequences, including making us vulnerable to general adverse economic and industry conditions, limiting our ability to borrow additional funds and placing us at competitive disadvantages compared with our competitors that have less debt;

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an event of default may require us to offer to repurchase certain of our or ONEOK Partners, L.P.’s senior notes or may impair our ability to access capital;

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the right to receive payments on our outstanding debt securities and subsidiary guarantees is unsecured and effectively subordinated to any future secured indebtedness and any existing and future indebtedness of our subsidiaries that do not guarantee the senior notes;

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use by a court of fraudulent conveyance to avoid or subordinate the cross guarantees of our or ONEOK Partners, L.P.’s indebtedness;

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the risks associated with pending or possible acquisitions and dispositions, including our ability to finance or integrate any such acquisitions and any regulatory delay or conditions imposed by regulatory bodies in connection with any such acquisitions and dispositions;

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our ability to effectively manage our expanded operations following closing of recent and potential future acquisitions;

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our ability to pay dividends;

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our exposure to the credit risk of our customers or counterparties;

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a shortage of skilled labor;

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misconduct or other improper activities engaged in by our employees;

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the impact of potential impairment charges;

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the impact of the changing cost of providing pension and health care benefits, including postretirement health care benefits, to eligible employees and qualified retirees;

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our ability to maintain an effective system of internal controls; and

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the risk factors listed in the reports we have filed and may file with the SEC.

These factors are not necessarily all of the important factors that could cause actual results to differ materially from those expressed in any of our forward-looking statements. Other factors could also adversely affect our future results. These and other risks are described in greater detail in Part I, Item 1A, “Risk Factors,” in our Annual Report on Form 10-K for the year ended December 31, 2025, and Part II, Item 1A, “Risk Factors,” in our Quarterly Report on Form 10-Q for the period ended March 31, 2026, and in our other filings that we make with the SEC, which are available via the SEC’s website at www.sec.gov and our website at www.oneok.com. All forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by these factors. Any such forward-looking statement speaks only as of the date on which such statement is made, and other than as required under securities laws, we undertake no obligation to update publicly any forward-looking statement whether as a result of new information, subsequent events or change in circumstances, expectations or otherwise.

ABOUT ONEOK

We are incorporated under the laws of the state of Oklahoma, and our common stock is listed on the New York Stock Exchange under the trading symbol “OKE.” We deliver energy products and services vital to an advancing world. We are a leading midstream service provider of gathering, processing, fractionation, transportation, storage and marine export services. As one of the largest integrated energy infrastructure companies in North America, we are delivering energy that makes a difference in the lives of people in the U.S. and around the world. Through our approximately 60,000-mile pipeline network, we transport the natural gas, NGLs, Refined Products and crude oil that help meet domestic and international energy demand, contribute to energy security and provide safe, reliable and responsible energy solutions needed today and into the future.

RISK FACTORS

Before you invest in our securities, you should carefully consider those risk factors included in our most recent Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q and our other filings with the SEC that are incorporated herein by reference and any prospectus supplement or free writing prospectus used in connection with an offering of our securities, as well as the information relating to us identified above under “Cautionary Statement Regarding Forward-Looking Statements.”

If any of the risks discussed in the foregoing documents were actually to occur, our business, financial condition, results of operations, or cash flow could be materially adversely affected. In that case, our ability to pay dividends to our shareholders or pay interest on, or the principal of, any debt securities, may be reduced, the trading price of our securities could decline and you could lose all or part of your investment.

USE OF PROCEEDS

Unless we inform you otherwise in an applicable prospectus supplement, ONEOK will use the net proceeds from the sale of the offered securities for general corporate purposes. These purposes may include repayment and refinancing of debt, acquisitions, working capital, capital expenditures and repurchases and redemptions of securities. Pending any specific application, we may initially invest funds in marketable securities or apply them to the reduction of short-term indebtedness.

DESCRIPTION OF DEBT SECURITIES

The following description states the general terms and provisions of our debt securities. The debt securities offered by this prospectus will be issued under one of two separate indentures among us, ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., Elk Merger Sub II, L.L.C. (f/k/a EnLink Midstream, LLC), EnLink Midstream Partners, LP (together with ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and Elk Merger Sub II, L.L.C. the “Guarantors”), and U.S. Bank Trust Company, National Association (as successor in interest to U.S. Bank National Association), as trustee. We have filed the forms of indenture as exhibits to the registration statement of which this prospectus is a part. The debt securities will be unsecured obligations of ONEOK and will be either senior or subordinated debt. Senior debt will be issued under a senior indenture (the “senior indenture”) and subordinated debt will be issued under a subordinated indenture (the “subordinated indenture”). The senior indenture and the subordinated indenture are sometimes referred to in this prospectus individually as an “Indenture” and collectively as the “Indentures.” Each prospectus supplement that we provide when we offer debt securities will describe the specific terms of the debt securities offered through that prospectus supplement and any general terms outlined in this section that will not apply to those debt securities. Unless otherwise specified in this prospectus, the term “debt securities” includes senior debt securities and subordinated debt securities and the descriptions of the debt securities describe both the senior debt securities and the subordinated debt securities unless otherwise specified in this prospectus or any prospectus supplement.

We have summarized the material terms and provisions of the Indentures in this section. The summary is not complete. We have filed the forms of each of the Indentures as exhibits to the registration statement of which this prospectus forms a part. You should read the applicable form of Indenture for additional information before you buy any debt securities. Each of the Indentures is qualified under the Trust Indenture Act. You should refer to the Trust Indenture Act for provisions that apply to the debt securities. This summary also is subject to and qualified by reference to the description of the particular terms of the debt securities described in the applicable prospectus supplement or supplements and pricing supplement or supplements. Capitalized terms used but not defined in this summary have the meanings specified in the applicable Indenture. In this section, “we,” “us” and “our” refer only to ONEOK, Inc. and not to any of our subsidiaries.

Debt securities issued under either Indenture will be issued as part of a series that will be established pursuant to a supplemental indenture or other authorized corporate action designating the specific terms of the series of debt securities. A prospectus supplement will describe these terms and will include, among other things, the following:

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the title of the debt securities of the particular series and whether the debt securities will be senior debt securities or subordinated debt securities;

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the total principal amount of those debt securities and the percentage of their principal amount at which we will issue those debt securities;

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the date or dates on which the principal of those debt securities will be payable;

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the interest rate, the method for determining the interest rate (if the interest rate is variable), the date from which interest will accrue, interest payment dates and record dates for interest payments;

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the place or places where payments on those debt securities will be made, where holders may surrender their debt securities for transfer or exchange and where to serve notices or demands;

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any provisions for optional redemption or early repayment;

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any provisions that would obligate us to redeem, purchase or repay those debt securities;

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any provisions for conversion or exchange of the debt securities;

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whether payments on the debt securities of the particular series will be payable by reference to any index, formula or other method;

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any deletions from, changes of or additions to the events of default, covenants or other provisions described in this prospectus;

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the portion of the principal amount of those debt securities that will be payable if the maturity is accelerated, if other than the entire principal amount;

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any additional means of defeasance of all or any portion of those debt securities, any additional conditions or limitations to defeasance of those debt securities or any changes to those conditions or limitations;

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any provisions granting special rights to holders of the debt securities of the particular series upon the occurrence of events identified in the prospectus supplement;

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if other than the trustee, the designation of any paying agent or security registrar for those debt securities and the designation of any transfer or other agents or depositories for those debt securities;

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whether we will issue the debt securities of the particular series in individual physical certificates to each holder or in the form of temporary or permanent global securities that a depository will hold on behalf of holders;

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the denominations in which we will issue the debt securities of the particular series or in which they may be owned, if other than $1,000 or any integral multiple of $1,000;

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whether the debt securities of such series will be guaranteed by the Guarantors pursuant to the guarantee provisions of the Indenture governing such series, any modifications to the terms of such provisions applicable to the debt securities of such series and the applicability of any other guarantees; and

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any other terms or conditions that are consistent with such Indenture, which may include the applicability of or change in the subordination provisions of such Indenture or providing collateral, security or assurance for a series of debt securities.

We may sell the debt securities at a discount (which may be substantial) below their stated principal amount. These discounted debt securities may bear no interest or interest at a rate that at the time of issuance is below market rates. We will describe in the prospectus supplement any material United States federal income tax consequences and other special considerations.

Certain Restrictive Covenants Under Our Senior Indenture

Under the senior indenture, we have agreed to two principal restrictions on our activities for the benefit of holders of the senior debt securities. The restrictive covenants summarized below will apply to a series of senior debt securities (unless waived or amended) as long as any of those senior debt securities are outstanding or, unless the prospectus supplement for the series states otherwise. We have used in this summary description capitalized terms that we have defined below under “—Glossary.” Our Restricted Subsidiaries are those that own or lease a Principal Property.

Other than the restrictions on Liens and Sale/Leaseback transactions under the senior indenture described below, the Indentures and the debt securities do not contain any covenants or other provisions designed to protect holders of any debt securities in the event we participate in a highly leveraged transaction. The Indentures and the debt securities also do not contain provisions that give holders of the debt securities the right to require us to repurchase their securities in the event of change-in-control, recapitalization or similar restructuring or otherwise or upon a decline in our credit rating.

For these purposes, “debt” means obligations for money borrowed, evidenced by notes, bonds, debentures or other similar evidences of indebtedness.

Limitation on Liens

We agree that we will not, and will not permit any Restricted Subsidiary to, create, incur, issue or assume any debt secured by any Lien on any Principal Property, or on shares of stock or debt of any Restricted Subsidiary, without making effective provision for the outstanding securities issued under the senior indenture (except as otherwise specified pursuant to an applicable supplemental indenture) to be secured by the Lien equally and ratably with (or prior to) any and all debt and obligations secured or to be secured thereby for so long as such debt is so secured, except that the foregoing restriction will not apply to:

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Any Lien existing on the date of the first issue of securities under the senior indenture.

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Any Lien on any Principal Property or Restricted Securities of any Person existing at the time such Person is merged or consolidated with or into us or a Restricted Subsidiary, or such Person becomes a Restricted Subsidiary.

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Any Lien on any Principal Property existing at the time of acquisition of such Principal Property by us or a Restricted Subsidiary, whether or not assumed by us or such Restricted Subsidiary, provided that no such Lien may extend to any other Principal Property of ours or of any Restricted Subsidiary.

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Any Lien on any Principal Property (including any improvements on an existing Principal Property) of ours or of any Restricted Subsidiary, and any Lien on the shares of stock of a Restricted Subsidiary that was formed or is held for the purpose of acquiring and holding such Principal Property, in each case to secure all or any part of the cost of acquisition, development, operation, construction, alteration, repair or improvement of all or any part of such Principal Property (or to secure Indebtedness incurred by us or a Restricted Subsidiary for the purpose of financing all or any part of such cost); provided that such Lien is created prior to, at the time of, or within 12 months after the latest of, the acquisition, completion of construction or improvement or commencement of commercial operation of such Principal Property and provided, further, that no such Lien may extend to any other Principal Property of us or any Restricted Subsidiary, other than any theretofore unimproved real property on which the Principal Property is so constructed or developed or the improvement is located.

•

Any Lien on any Principal Property or Restricted Securities to secure debt owing to us or to another Restricted Subsidiary.

•

Any Lien in favor of governmental bodies to secure advances or other payments pursuant to any contract or statute or to secure debt incurred to finance the purchase price or cost of constructing or improving the property subject to such Lien.

•

Any Lien created in connection with a project financed with, and created to secure, non-recourse indebtedness.

•

Carriers’, warehousemen’s, mechanics’, landlords’, materialmen’s, repairmen’s or other similar Liens arising in the ordinary course of business which are not delinquent or remain payable without penalty or which are being contested in good faith and by appropriate proceedings.

•

Liens (other than Liens imposed by Employee Retirement Income Security Act of 1974) on the property of ours or any of our Restricted Subsidiaries incurred, or pledges or deposits required, in connection with workmen’s compensation, unemployment insurance and other social security legislation.

•

Liens securing taxes that remain payable without penalty or which are being contested in good faith by appropriate proceedings where collection thereof is stayed; provided that we have or any Restricted Subsidiary has set aside on its books reserves with respect to such taxes (segregated to the extent required by GAAP) deemed by it to be adequate.

•

Any right which any municipal or governmental body or agency may have by virtue of any franchise, license or contract to purchase or designate a purchaser of, or order the sale of, any property of ours upon payment of reasonable compensation therefor or to terminate any franchise, license or other rights or to regulate our property and business.

•

Any Liens, neither assumed by us or any Restricted Subsidiary or on which we or any Restricted Subsidiary customarily pays interest, existing upon real estate or rights in or relating to real estate acquired by us or any Restricted Subsidiary for sub-station, measuring station, regulating station, gas purification station, compressor station, transmission line, distribution line or right-of-way purposes.

•

Easements or reservations in any property of ours or of any Restricted Subsidiary for the purpose of roads, pipe lines, gas transmission and distribution lines, electric light and power transmission and distribution lines, water mains and other like purposes, and zoning ordinances, regulations and restrictions which do not impair the use of such property in the operation of the business of ours or of any Restricted Subsidiary.

•

Any extension, renewal, substitution or replacement (or successive extensions, renewals, substitutions or replacements), in whole or in part, of any Lien referred to in above, provided that the debt secured thereby may not exceed the principal amount of debt so secured at the time of such renewal or refunding, and that such renewal or refunding Lien must be limited to all or any part of the same property and improvements thereon, shares of stock or debt that secured the Lien renewed or refunded.

•

Any Lien prohibited above securing debt that, together with the aggregate outstanding principal amount of other secured debt that would otherwise be subject to the foregoing restrictions (excluding debt secured by Liens not prohibited under the foregoing exceptions) and the Attributable Debt in respect of all Sale and Leaseback Transactions (not including Attributable Debt in respect of any such Sale and Leaseback Transactions described in the third and fourth “bullet points” in “Limitations on Sale and Leaseback Transactions”) would not then exceed 15% of Consolidated Net Tangible Assets.

Limitation on Sale/Leaseback Transactions

We agree that we will not, and will not permit any Restricted Subsidiary to, enter into any Sale and Leaseback Transaction unless:

•

we or a Restricted Subsidiary would be entitled, without securing the outstanding securities under the senior indenture, to incur debt secured by a Lien on the Principal Property that is the subject of such Sale and Leaseback Transaction;

•

the Attributable Debt associated therewith would be in an amount not prohibited under “Limitation on Liens”;

•

the proceeds received in respect of the Principal Property so sold and leased back at the time of entering into such Sale and Leaseback Transaction are used for the business and operations of us or any subsidiary; or

•

within 12 months after the sale or transfer, an amount equal to the proceeds received in respect of the Principal Property so sold and leased back at the time of entering into such Sale and Leaseback Transaction is applied to the prepayment (other than mandatory prepayment) of any outstanding securities issued under the senior indenture or Funded Indebtedness of ours or of a Restricted Subsidiary (other than Funded Indebtedness that is held by us or any Restricted Subsidiary or Funded Indebtedness of ours that is subordinate in right of payment to any outstanding securities issued under the senior indenture).

Glossary

“Attributable Debt” means, as to any particular Sale and Leaseback Transaction under which any Person is at the time liable, at any date as of which the amount thereof is to be determined, the total net amount of rent required to be paid by that Person under the lease during the remaining term thereof (excluding amounts required to be paid on account of maintenance and repairs, services, insurance, taxes, assessments, water rates and similar charges and contingent rents), discounted from the respective due dates thereof at the weighted average of the rates of interest (or yield to maturity, in the case of senior debt securities originally sold at a discount) borne by the debt securities then outstanding under the senior indenture, compounded annually.

“Consolidated Net Tangible Assets” means the total amount of assets (less applicable reserves and other properly deductible items) that under generally accepted accounting principles, or GAAP, would be included on a consolidated balance sheet of ours and our subsidiaries after deducting therefrom (A) all current liabilities, provided, however, that there will not be deducted billings recorded as revenues deferred pending the outcome of rate proceedings (less applicable income taxes thereon), if and to the extent the obligation to refund the same has not been finally determined, (B) appropriate allowance for minority interests in common stocks of subsidiaries and (C) all goodwill, trade names, trademarks, patents, unamortized debt discount and expense and other like intangibles, which in each case under GAAP would be included on the consolidated balance sheet.

“Funded Indebtedness” as applied to any Person, means all debt evidenced by notes, bonds, debentures or other similar evidences of indebtedness, of that Person maturing after, or renewable or extendable at that Person’s option beyond, 12 months from the date of determination.

“Lien” means any lien, mortgage, pledge, encumbrance, charge or security interest securing debt; provided, however, that the following types of transactions will not be considered for purposes of this definition to result in a Lien: (1) any acquisition by us or any of our Restricted Subsidiaries of any property or assets subject to any reservation or exception under the terms of which any vendor, lessor or assignor creates, reserves or excepts or has created, reserved or excepted an interest in oil, gas or any other mineral in place or the proceeds thereof, (2) any conveyance or assignment whereby we or any Restricted Subsidiary convey or assign to any Person or Persons an interest in oil, gas or any other mineral in place or the proceeds thereof, (3) any Lien upon any property or assets either owned or leased by us or any Restricted Subsidiary or in which we or any Restricted Subsidiary own an interest that secures for the benefit of the Person or Persons paying the expenses of developing or conducting operations for the recovery, storage, transportation or sale of the mineral resources of the property or assets (or property or assets with which it is unitized) the payment to that Person or Persons of our or a Restricted Subsidiary’s proportionate part of such development or operating expenses or (4) any hedging arrangements entered into in the ordinary course of business, including any obligation to deliver any mineral, commodity or asset in connection therewith.

“Person” means any individual, corporation, partnership, limited liability company, joint venture, association, joint-stock company, trust, unincorporated organization or government or any agency or political subdivision thereof.

“Principal Property” means any property located in the United States, except any property that in the opinion of our board of directors is not of material importance to the total business conducted by us and our consolidated subsidiaries.

“Restricted Securities” means shares of stock or debt of any Restricted Subsidiary.

“Restricted Subsidiary” means any subsidiary that owns or leases Principal Property.

“Sale/Leaseback Transaction” means any arrangement with any Person pursuant to which we or any Restricted Subsidiary lease any Principal Property that has been or is to be sold or transferred by us to that Person, other than (1) a lease for a term, including renewals at the option of the lessee, of not more than three years or classified as an operating lease under GAAP, (2) leases between us and a Restricted Subsidiary or between Restricted Subsidiaries, (3) leases of a Principal Property executed by the time of, or within 12 months after the latest of, the acquisition, the completion of construction or improvement, or the commencement of commercial operation, of the Principal Property and (4) the ground lease for ONEOK Plaza, 100 West Fifth Street, Tulsa, Oklahoma 74103.

Consolidation, Merger and Sale of Assets

The Indentures generally permit a consolidation or merger between us and another entity. They also permit the sale by us of all or substantially all of our assets. We have agreed, unless we inform you otherwise in the prospectus supplement, however, that we will consolidate with or merge into any entity or transfer or dispose of all or substantially all of our assets to any entity only if:

•

immediately after giving effect to the transaction, no default or event of default under either of the Indentures would have occurred and be continuing or would result from the transaction;

•

we are the continuing corporation or, if we are not the continuing corporation, the resulting entity is organized and existing under the laws of any United States jurisdiction and assumes the due and punctual payments on the debt securities and the performance of our covenants and obligations under the Indenture and those debt securities; and

•

we provide the trustee with a certificate and a legal opinion, each stating that the applicable Indenture does not prohibit the transaction.

Under the senior indenture, if we engage in any of these transactions that result in any Principal Property or shares of stock or debt of any Restricted Subsidiary becoming subject to any Lien and unless we are otherwise able to create that Lien, the senior debt securities (so long as those senior debt securities are entitled to the protection of the “Limitation on Liens” covenant) will be secured to at least the same extent as the debt that would become secured by the Lien as a result of the transaction.

The provisions of this covenant will not apply to any merger of us with or into any Guarantor or any Guarantor with or into another Guarantor.

Events of Default

Unless we inform you otherwise in the prospectus supplement, the following are events of default for a series of debt securities:

•

our failure to pay interest on that series of debt securities for 30 days after it becomes due and payable;

•

our failure to pay principal of or any premium on that series of debt securities when due;

•

our failure to comply with any of our covenants or agreements for that series of debt securities or in the applicable Indenture (other than an agreement or covenant that we have included in such Indenture solely for the benefit of less than all series of debt securities) for 60 days after the trustee or the holders of at least 33% in principal amount of all outstanding debt securities affected by that failure provide written notice to us;

•

various events involving our bankruptcy, insolvency or reorganization; or

•

any other event of default provided for that series of debt securities.

A default under one series of debt securities will not necessarily be a default under another series. The trustee may withhold notice to the holders of a series of debt securities of any default or event of default (except in any payment on that series of debt securities) if the trustee considers it in the interest of the holders of that series of debt securities to do so.

If an event of default for any series of debt securities occurs and is continuing, the trustee or the holders of at least 33% in principal amount of the outstanding debt securities of the series affected by the default (or, in some cases, 33% in principal amount of all debt securities affected, voting as one class) may require us to pay on an accelerated basis the principal of and all accrued and unpaid interest on those debt securities; provided that no such declaration of acceleration may be made with respect to any action taken, and reported publicly or to holders, more than two years prior to such declaration. The holders of a majority in principal amount of the outstanding debt securities of the series affected by the default (or of all debt securities affected, voting as one class) may in some cases rescind this accelerated payment requirement.

If an event of default occurs and is continuing, the trustee must use the degree of care and skill of a prudent person under the circumstances in the conduct of such person’s own affairs. The trustee will become obligated to exercise any of its powers under the applicable Indenture at the request of any of the holders of any debt securities only after those holders have offered the trustee indemnity reasonably satisfactory to the trustee.

The holders of a majority in principal amount of debt securities of any series have the right to waive past defaults under the applicable Indenture that relate to that series except for a default in the payment on the debt securities or a provision that can only, under the applicable Indenture, be modified or amended if all holders that are affected consent.

In most cases, holders of a majority in principal amount of the outstanding debt securities of a series (or of all debt securities affected, voting as one class) may direct the time, method and place of:

•

conducting any proceeding for any remedy available to the trustee; and

•

exercising any trust or power conferred on the trustee.

The Indentures require us to file each year with the trustee a written statement as to our compliance with the covenants contained in the Indentures.

Modification and Waiver

We and each guarantor (if any) may amend or supplement either of the Indentures if the holders of a majority in principal amount of the outstanding debt securities of all series that the amendment or supplement affects (acting as one class) consent to it. Without the consent of the holder of each debt security affected, however, no modification may:

•

reduce the principal of the debt security or change its stated maturity;

•

reduce the rate of or change the time for payment of interest on the debt security;

•

reduce any premium payable on the redemption of the debt security or change the time at which the debt security may or must be redeemed;

•

change any obligation to pay additional amounts on the debt security;

•

impair the holder’s right to institute suit for the enforcement of any payment on the debt security;

•

impair the holder’s right to convert or exchange any debt security;

•

reduce the percentage of principal amount of debt securities whose holders must consent to an amendment to or supplement of the applicable Indenture;

•

reduce the percentage of principal amount of debt securities necessary to waive compliance with some of the provisions of the applicable Indenture; or

•

modify provisions relating to amendment or waiver, except to increase percentages or to provide that other provisions of the applicable Indenture cannot be amended or waived without the consent of each holder affected.

We and each guarantor (if any) may amend or supplement either of the Indentures or waive any provision of such Indenture without the consent of any holders of debt securities in various circumstances, including:

•

to provide for the assumption of our obligations under the applicable Indenture and the debt securities by a successor;

•

to add covenants that would benefit the holders of any debt securities or to surrender any of our rights or powers;

•

to provide for the issuance of additional securities, including debt securities of a particular series, under the applicable Indenture;

•

to add events of default;

•

to provide any security for or guarantees of any series of debt securities;

•

to provide for the form or terms of any series of debt securities;

•

to appoint a successor trustee or to provide for the administration of the trusts under the applicable Indenture by more than one trustee;

•

to cure any ambiguity, omission, defect or inconsistency that does not adversely affect the interests of the holders of outstanding debt securities of any series;

•

to make any change to the extent necessary to permit or facilitate defeasance or discharge of any series of debt securities that does not adversely affect the interests of the holders of outstanding debt securities of any series;

•

to convey, transfer, assign, mortgage or pledge any property to or with the trustee;

•

to permit the qualification of the applicable Indenture under the Trust Indenture Act;

•

to change or eliminate any restriction on the payment of principal of, or premium, if any, on, any debt securities;

•

to add to, change or eliminate any of the provisions of the applicable Indenture in respect of one or more series of debt securities; provided, however, that any such addition, change or elimination not otherwise permitted shall neither apply to any debt security of any series created prior to the execution of such supplemental indenture and entitled to the benefit of such provision nor modify the rights of the holder of any such debt security with respect to such provision or shall become effective only when there is no such debt security outstanding;

•

reflect the release of any guarantor of its obligations under the guarantee, in the manner provided by the indenture; or

•

to make any change that does not affect the rights of any holder.

The holders of a majority in principal amount of the outstanding debt securities under either Indenture may waive our obligations to comply with various covenants, including those relating to:

•

our obligation to secure the debt securities in the event of mergers, consolidations and sales of assets;

•

corporate existence;

•

with respect to the senior debt securities, the restrictions on Liens and Sale/Leaseback Transactions; and

•

defeasance.

When we use the term defeasance, we mean discharge from some or all of our obligations under either Indenture. If we deposit with the trustee funds or government securities the maturing principal and interest of which is sufficient to make payments on the debt securities of a series on the dates those payments are due and payable, then, at our option, either of the following will occur:

•

“legal defeasance,” which means that we and each guarantor (if any) will be discharged from our obligations with respect to the debt securities of that series; or

•

“covenant defeasance,” which means that we will no longer have any obligation to comply with the restrictive covenants under the applicable Indenture and any other restrictive covenants that apply to that series of the debt securities, and the related events of default will no longer apply to us.

If we defease a series of debt securities, the holders of the debt securities of the series affected will not be entitled to the benefits of the applicable Indenture, to provide temporary debt securities, to register the transfer or exchange of debt securities, to replace stolen, lost or mutilated debt securities or to maintain paying agencies and hold money for payment in trust. In the case of covenant defeasance, our obligation to pay principal, premium and interest on the debt securities will also survive.

Unless we inform you otherwise in the prospectus supplement, we will be required to deliver to the trustee an opinion of counsel that the deposit and related defeasance would not cause the holders of the debt securities to recognize income, gain or loss for federal income tax purposes. If we elect legal defeasance, that opinion of counsel must be based upon a ruling from the Internal Revenue Service or a change in law to that effect.

Certain Waivers and Limitations

No past, present or future director, officer, employee, manager, member, partner, incorporator or stockholder of ONEOK, Inc. or any guarantor, or any employee or agent of any affiliate of ONEOK, Inc., or any guarantor who has been seconded to ONEOK, Inc., any guarantor or any of their respective subsidiaries, as such, will have any liability for any obligations of ONEOK, Inc. or any guarantor under the debt securities or any Indenture or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each holder of debt securities by accepting a debt security waives and releases all such liability. The waiver and release are part of the consideration for issuance of the debt securities. The waiver may not be effective to waive liabilities under the federal securities laws. The only payment provisions, representations and warranties, covenants, events of default, guarantee provisions and other obligations applicable to ONEOK, Inc. and any guarantor are those expressly set forth in the Indenture and, by acceptance of any Note, each holder waives and expressly disclaims to the maximum extent permitted by applicable law any implied covenant and other similar provision that may exist in law or in equity and that may be applicable to ONEOK, Inc. or any guarantor and each holder agrees that it will not participate in any cause of action with respect to, alleging the existence or breach of, or seeking to enforce any such implied covenant or similar provision. In addition, the “integrated transaction doctrine” or any similar legal doctrine or theory is expressly waived by each holder by acceptance of any Note. Without limiting the foregoing, each holder agrees by acceptance of any Note that (a) any series of related transactions shall be permitted by any Indenture if each individual transaction would be permitted, and (b) any series of related transactions that are consummated substantially concurrently may be deemed to be consummated in any order determined by ONEOK, Inc. that complies with the Indenture with permissibility of each transaction evaluated in light of such order.

Subordination Provisions for Subordinated Debt Securities

Any subordinated debt securities issued under the subordinated indenture will be subordinate and subject in right of payment to the prior payment in full of all of our Senior Indebtedness. The following provisions will apply to the subordinated debt securities unless otherwise specified in the prospectus supplement:

Subject to any collateral, security, assurance or guarantee provided for the benefit of any series of subordinated debt securities, if any, the payment of principal, any premium and interest on the subordinated debt securities will be subordinated in right of payment to the prior payment in full of all of our Senior Indebtedness. This means that in certain circumstances where we may not be making payments on all of our debt obligations as they become due, the holders of all of our Senior Indebtedness will be entitled to receive payment in full of all amounts that are due or will become due on the Senior Indebtedness before the holders of subordinated debt securities will be entitled to receive any payment or distribution (other than in the form of subordinated securities) on the subordinated debt securities. These circumstances include the following circumstances:

•

we make a payment or distribute assets to creditors upon any liquidation, dissolution, winding up or reorganization of our company, or as part of an assignment or marshalling of our assets for the benefit of our creditors;

•

we file for bankruptcy or certain other events in bankruptcy, insolvency or similar proceedings occur; and

•

the maturity of the subordinated debt securities is accelerated. For example, the entire principal amount of a series of subordinated debt securities may be declared to be due and immediately payable or may be automatically accelerated due to an event of default as described under “—Events of Default.”

In addition, we are generally not permitted to make payments of principal, any premium or interest on the subordinated debt securities if we default on our obligation to make payments on our Senior Indebtedness and do not cure such default. We are also prohibited from making payments on subordinated debt securities if an event of default (other than a payment default) that permits the holders of senior indebtedness to accelerate the maturity of the Senior Indebtedness occurs and we and the trustee have received a notice of such event of default. However, unless the senior indebtedness has been accelerated because of that event of default, this payment blockage upon notice cannot last more than 179 days.

These subordination provisions mean that if we are insolvent a holder of Senior Indebtedness is likely to ultimately receive out of our assets more than a holder of the same amount of our subordinated debt securities, and a creditor of ours that is owed a specific amount but who owns neither our Senior Indebtedness nor our subordinated debt securities may ultimately receive less than a holder of the same amount of Senior Indebtedness and more than a holder of subordinated debt securities.

The subordinated indenture does not limit the amount of senior indebtedness we are permitted to have and we may in the future incur additional senior indebtedness.

“Senior Indebtedness” is defined in the subordinated indenture to mean, with respect to us,

(i)

the principal, premium, if any, and interest (including interest, whether or not allowable, accruing after the filing of a petition initiating any proceeding under any state, federal or foreign bankruptcy law) in respect of (A) our indebtedness and obligations related thereto and (B) indebtedness evidenced by securities, debentures, notes, bonds or other similar instruments issued by us;

(ii)

all our finance lease, purchase money and similar obligations;

(iii)

all our obligations issued or assumed as the deferred purchase price of property, all our conditional sale obligations and all our obligations under any title retention agreement;

(iv)

all our obligations for the reimbursement of any letter of credit, any banker’s acceptance, any security purchase facility, any repurchase agreement or similar arrangement, any commercial paper, any interest rate swap, any other hedging arrangement, or any obligation under options or any similar credit or other transaction;

(v)

all obligations for indemnification, contributions, earnouts, adjustments of purchase price or similar obligations;

(vi)

all obligations in respect of workers compensation claims, self-insurance, indemnities, bid performance, warranty release, appeal, surety and similar bonds;

(vii)

all obligations of the type referred to in clauses (i) through (vi) above of other Persons for the payment of which we are responsible or liable as obligor, guarantor or otherwise;

(viii)

all obligations of the type referred to in clauses (i) through (vii) above of other Persons secured by any lien on any property or asset of ours (whether or not such obligation is assumed by us); and

(ix)

all renewals, extensions, modifications and refunding of obligations of the type referred to in clauses (i) through (viii) above; whether incurred on or prior to the date of the subordinated indenture or thereafter incurred. Notwithstanding the foregoing, “Senior Indebtedness” shall not include (1) any Additional Junior Indebtedness, (2) debt securities issued pursuant to the subordinated indenture and guarantees in respect of such debt securities, (3) our trade accounts payable arising in the ordinary course of business (such trade accounts payable being pari passu in right of payment to debt securities issued pursuant to the subordinated indenture), or (4) obligations with respect to which in the instrument creating or evidencing the same or pursuant to which the same is outstanding, it is provided that such obligations are pari passu or junior in right of payment to debt securities issued pursuant to the subordinated indenture. Senior Indebtedness shall continue to be Senior Indebtedness and be entitled to the subordination provisions irrespective of any amendment, modification or waiver of any term of such Senior Indebtedness.

“Additional Junior Indebtedness” is defined in the subordinated indenture to mean, without duplication and other than the subordinated debt securities, any indebtedness, liabilities, guarantees or obligations of ours or any of our subsidiaries, under debt securities (or guarantees in respect of debt securities or preferred securities) initially issued after the date of the subordinated indenture to any trust, or a trustee of a trust, partnership or other entity affiliated with us that is, directly or indirectly, a finance subsidiary (as such term is defined in Rule 3a-5 under the Investment Company Act of 1940) or other financing vehicle of ours or any subsidiary of ours in connection with the issuance by that entity of preferred securities or other securities that are issued on a pari passu basis with the subordinated debt securities.

If this prospectus is being delivered in connection with a series of subordinated securities, the accompanying prospectus supplement or the information incorporated by reference will set forth the approximate amount of senior indebtedness outstanding as of a recent date.

Guarantee

To the extent provided in a prospectus supplement and either a supplemental indenture or a resolution of our board of directors, in each case, relating to a particular series of debt securities, each of our subsidiaries that becomes a guarantor of the debt securities of such series, and any of our subsidiaries that is a successor thereto, will fully, irrevocably, unconditionally and absolutely guarantee the due and punctual payment of the principal of, and premium, if any, and interest on such debt securities, and all other amounts due and payable under the applicable indenture and such debt securities by us to the trustee or the holders of such debt securities, however, such guarantors will not otherwise be subject to the covenants, obligations and duties provided for in the indenture solely in their capacity as guarantors.

Satisfaction and Discharge

The Indentures will cease to be of further effect and will be deemed to have been satisfied and discharged with respect to a particular series of debt securities, when the following conditions have been satisfied:

•

all debt securities of that series have been delivered to the trustee for cancellation, or all debt securities of that series not previously delivered to the trustee for cancellation have become due and payable or will become due and payable at their stated maturity or on a redemption date within one year, and we:

•

irrevocably deposit with the trustee, in trust, funds sufficient to pay and discharge the entire indebtedness on the senior debt securities of that series that had not been previously delivered for cancellation, for principal (and premium, if any) and interest, if any, to the date of the deposit (for debt securities that have become due and payable) or to the stated maturity or the redemption date, as the case may be;

•

have paid or caused to be paid all other sums payable under the applicable Indenture or have made arrangements for any such payments satisfactory to the payee; and

•

have delivered to the trustee an officer’s certificate and opinion of counsel, each stating that all these conditions precedent provided for satisfaction and discharge of the Indenture have been complied with.

Governing Law

New York law governs the Indentures and the debt securities. We, the trustee and the holders (by acceptance of the debt securities) each irrevocably waive, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to the Indentures, the debt securities or the transactions contemplated thereby. In addition, any legal suit, action or proceeding arising out of or based upon the Indentures or the transactions contemplated thereby may be instituted in the federal courts of the United States located in the City of New York or the courts of the State of New York located in the City of New York (collectively, the “Specified Courts”), and we, the trustee and the holders (by acceptance of the debt securities) each irrevocably submit to the non-exclusive jurisdiction of such courts. We, the trustee and the holders (by their acceptance of the debt securities) irrevocably waive any objection to the laying of venue of any suit, action or other proceeding in the Specified Courts and irrevocably waive and agree not to plead or claim any such suit, action or other proceeding has been brought in an inconvenient forum.

Trustee

U.S. Bank Trust Company, National Association (as successor to U.S. Bank National Association) is trustee under the Indentures. The Indentures provide that, except during the continuance of an event of default, the trustee will perform only such duties as are specifically set forth in the Indentures. The Indentures contain limitations on the right of the trustee, if it becomes one of our creditors, to obtain payment of claims or to realize payment on property received for those claims, as security or otherwise. The trustee is permitted to engage in other transactions with us in the ordinary course of business. If, however, it acquires any conflicting interest, it must eliminate that conflict or resign. Affiliates of the trustee may engage in other transactions with us in the ordinary course of business from time to time.

Form, Exchange, Registration and Transfer

We will issue the debt securities in registered form, without interest coupons. We will not charge a service charge for any registration of transfer or exchange of the debt securities. We may, however, require the payment of any tax or other governmental charge payable for that registration.

Holders may exchange debt securities of any series for other debt securities of the same series, the same total principal amount and the same terms but in different authorized denominations in accordance with the

applicable Indenture. Holders may present debt securities for registration of transfer at the office of the security registrar or any transfer agent we designate. The security registrar or transfer agent will effect the transfer or exchange when it is satisfied with the documents of title and identity of the person making the request.

We have appointed the trustee as security registrar for the debt securities. If a prospectus supplement refers to any transfer agent initially designated by us, we may at any time rescind that designation or approve a change in the location through which any transfer agent acts. We are required to maintain an office or agency for transfers and exchanges in each place of payment. We may at any time designate additional transfer agents for any series of debt securities.

In the case of any redemption, neither the security registrar nor the transfer agent will be required to register the transfer or exchange of any debt security either:

•

during a period beginning 15 business days prior to the mailing of the relevant notice of redemption and ending on the close of business on the day of mailing of that notice; or

•

if we have called the debt security for redemption in whole or in part, except the unredeemed portion of any debt security being redeemed in part.

Payment and Paying Agents

Unless we inform you otherwise in a prospectus supplement, payments on the debt securities will be made in U.S. dollars at the office of the trustee. At our option, however, we may make payments by check mailed to the holder’s registered address or, for global debt securities, by wire transfer. Unless we inform you otherwise in a prospectus supplement, we will make interest payments to the person in whose name the debt security is registered at the close of business on the record date for the interest payment.

Unless we inform you otherwise in a prospectus supplement, we have designated the trustee as our paying agent for payments on debt securities issued under the Indentures. We may at any time designate additional paying agents or rescind the designation of any paying agent or approve a change in the office through which any paying agent acts.

Subject to the requirements of any applicable abandoned property laws, the trustee and paying agent will pay to us upon written request any money they are holding for payments on the debt securities that remain unclaimed for two years after the date upon which that payment has become due. After payment to us, holders entitled to the money must look to us for payment. In that case, all liability of the trustee or paying agent with respect to that money will cease.

Book-Entry Debt Securities

We may issue the debt securities of a series in the form of one or more global debt securities that would be deposited with a depositary or its nominee identified in the prospectus supplement. We may issue global debt securities in either temporary or permanent form. We will describe in the prospectus supplement the terms of any depositary arrangement and the rights and limitations of owners of beneficial interests in any global debt security.

DESCRIPTION OF GUARANTEE OF DEBT SECURITIES

To the extent provided in a prospectus supplement and either an indenture supplement or a resolution of our board of directors, in each case, relating to a particular series of debt securities, each of our subsidiaries that becomes a guarantor of the debt securities of such series, and any of our subsidiaries that is a successor thereto, will fully, irrevocably, unconditionally and absolutely guarantee the due and punctual payment of the principal

of, and premium, if any, and interest on such debt securities, and all other amounts due and payable under the applicable indenture and such debt securities by us to the trustee or the holders of such debt securities, and any provisions permitting a release of such guarantee will be included in such prospectus supplement and indenture supplement or resolution, however, such guarantors will not otherwise be subject to the covenants, obligations and duties provided for in the indenture solely in their capacity as guarantors.

DESCRIPTION OF CAPITAL STOCK

General

We are authorized to issue a total of 1,300,000,000 shares of all classes of capital stock. Of those authorized shares, 1,200,000,000 are shares of common stock, 630,147,442 shares of which were outstanding as of June 15, 2026, and 100,000,000 are shares of preferred stock. Of the authorized preferred stock, there are 20,000,000 shares designated as Convertible Preferred Stock, Series A (none of which was outstanding on June 18, 2026), 30,000,000 shares designated as Convertible Preferred Stock, Series B (none of which was outstanding on June 18, 2026), and 1,000,000 shares designated as Series C Participating Preferred Stock (none of which was outstanding on June 18, 2026).

The additional shares of our authorized stock available for issuance might be issued at times and under circumstances so as to have a dilutive effect on earnings per share and on the equity ownership of the holders of our common stock. The ability of our board of directors to issue additional shares of stock could enhance the board’s ability to negotiate on behalf of the shareholders in a takeover situation but could also be used by the board to make a change-in-control more difficult, thereby denying shareholders the potential to sell their shares at a premium and entrenching current management.

The following description is a summary of the material provisions of our capital stock and various provisions of our certificate of incorporation and bylaws. This summary is not intended to be complete and is qualified by reference to the provisions of applicable law and our certificate of incorporation and bylaws included as exhibits to the registration statement of which this prospectus is a part.

Common Stock

As of June 15, 2026, there were 14,269 holders of record. The issued and outstanding shares of common stock are validly issued, fully paid and non-assessable. Subject to any preferential rights of any prior ranking class or series of capital stock, including the preferred stock, holders of our common stock are entitled to receive dividends on that stock, payable either in cash, property or shares out of assets legally available for distribution when, as and if authorized and declared by our board of directors and to share ratably in our assets legally available for distribution to our shareholders in the event of liquidation, dissolution or winding-up. Subject to various exceptions, we will not be able to pay any dividend or make any distribution of assets on shares of our common stock until we pay dividends on any shares of preferred stock then outstanding with dividend or distribution rights senior to our common stock.

Holders of our common stock are entitled to one vote per share on all matters voted on by our shareholders, including the election of directors. Our certificate of incorporation does not provide for cumulative voting for the election of directors, which means that holders of more than one-half of the outstanding shares of our voting securities will be able to elect all of the directors then standing for election and holders of the remaining shares will not be able to elect any director.

Our board of directors may make rules and regulations concerning the transfer of shares of our common stock from time to time, in accordance with our bylaws.

Holders of our common stock will have no conversion, sinking fund or redemption rights.

Some provisions of the Oklahoma General Corporation Act, our certificate of incorporation and our bylaws may discriminate against holders of a substantial amount of the shares of our common stock. See “—Oklahoma Law” and “—Certificate of Incorporation and Bylaws.” Similarly, some provisions of our certificate of incorporation and our bylaws may have the effect of delaying, deferring or preventing a change-in-control with respect to an extraordinary corporate transaction, such as a merger, reorganization, tender offer, sale or transfer of substantially all of our assets.

Preferred Stock

Our board of directors is authorized to issue shares of preferred stock, in one or more series or classes, and to fix for each series or class the preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends, qualifications, or terms or redemption, as are permitted by Oklahoma law and as are stated in the resolution or resolutions adopted by the board providing for the issuance of shares of that series or class.

Our board has authorized series designated as Convertible Preferred Stock, Series A, Convertible Preferred Stock, Series B and Series C Participating Preferred Stock.

When we offer to sell a particular series of preferred stock, we will describe the specific terms of the securities in a supplement to this prospectus. The prospectus supplement will also indicate whether the terms and provisions described in this prospectus apply to the particular series of preferred stock. The preferred stock will be issued under a certificate of designations relating to each series of preferred stock. The issuance of our preferred stock is also subject to our certificate of incorporation.

Preemptive Rights

No holder of any shares of any class of our stock has any preemptive or preferential right to acquire or subscribe for any unissued shares of any class of stock or any unauthorized securities, convertible into or carrying any right, option or warrant to subscribe for or acquire shares of any class of stock.

Oklahoma Law

Oklahoma Takeover Statute

We are subject to Section 1090.3 of the Oklahoma General Corporation Act. In general, Section 1090.3 prevents an “interested shareholder” from engaging in a “business combination” with an Oklahoma corporation for three years following the date that person became an interested shareholder, unless:

•

prior to the date that person became an interested shareholder, the corporation’s board of directors approved the business combination or the transaction in which the interested shareholder became an interested shareholder;

•

upon consummation of the transaction that resulted in the interested shareholder becoming an interested shareholder, the interested shareholder owned at least 85% of the corporation’s voting stock outstanding at the time the transaction commenced, excluding stock held by directors who are also officers of the corporation and stock held by certain employee stock plans; or

•

on or subsequent to the date of the transaction in which that person became an interested shareholder, the business combination was approved by the corporation’s board of directors and authorized at a meeting of shareholders by the affirmative vote of the holders of at least two-thirds of the outstanding voting stock of the corporation not owned by the interested shareholder.

Section 1090.3 defines a “business combination” to include:

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any merger or consolidation involving the corporation and an interested shareholder;

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any sale, transfer, pledge or other disposition of 10% or more of the assets of the corporation involving an interested shareholder;

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subject to limited exceptions, any transaction that results in the issuance or transfer by the corporation of the stock of the corporation to an interested shareholder;

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any transaction involving the corporation that has the effect of increasing the proportionate share of the stock of any class or series of the corporation beneficially owned by the interested shareholder; or

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the receipt by an interested shareholder of any loans, guarantees, pledges or other financial benefits provided by or through the corporation.

For purposes of the description above and Section 1090.3, the term “corporation” also includes a corporation’s majority-owned subsidiaries. In addition, Section 1090.3, defines an “interested shareholder” as an entity or person beneficially owning 15% or more of a corporation’s outstanding voting stock and any entity or person affiliated with or controlling or controlled by that entity or person.

Oklahoma Control Share Provisions

Our certificate of incorporation provides that we are not subject to the control share provisions of the Oklahoma General Corporation Act. With exceptions, these provisions prevent holders of more than 20% of the voting power of the stock of an Oklahoma corporation from voting their shares. If we were to become subject to the control share provisions of the Oklahoma General Corporation Act in the future, this provision may delay the time it takes anyone to gain control of us.

Certificate of Incorporation and Bylaws

Exculpation

Our certificate of incorporation provides that our directors and officers will not be personally liable for monetary damages for any action taken, or any failure to take any action, unless:

•

the director or officer has breached his or her duty of loyalty to ONEOK or its shareholders;

•

the breach or failure to perform constitutes an act or omission not in good faith or which involves intentional misconduct or a knowing violation of law;

•

the director served at the time of payment of an unlawful dividend or an unlawful stock purchase or redemption, unless the director was absent at the time the action was taken or dissented from the action; or

•

the director or officer derived an improper personal benefit from the transaction.

Indemnification

We will generally indemnify any person who was, is, or is threatened to be made, a party to a proceeding by reason of the fact that he or she:

•

is or was our director, officer, employee or agent; or

•

is or was serving at our request as a director, officer, employee or agent of another corporation, partnership, limited liability company, joint venture, trust or other enterprise or as a member of any committee or similar body.

Any indemnification of our directors, officers or others pursuant to the foregoing provisions for liabilities arising under the Securities Act are, in the opinion of the SEC, against public policy as expressed in the Securities Act and are unenforceable.

Shareholder Action; Special Meeting of Shareholders

Our certificate of incorporation eliminates the ability of our shareholders to act by written consent. Our bylaws provide that special meetings of our shareholders may be called only by a majority of the members of our board of directors.

Advance Notice Requirements for Shareholder Proposals

At any annual meeting of our shareholders, the only business that shall be brought before the meeting is that which is brought:

•

pursuant to our notice of meeting;

•

by or at the discretion of our board of directors; or

•

by any of our shareholders of record at the time the notice is given, who are entitled to vote at the meeting and who comply with the notice procedures set forth in our bylaws as summarized below.

For business to be properly brought before an annual meeting by a shareholder pursuant to the immediately preceding clause, the shareholder must have given timely notice in writing to our secretary. To be timely as to an annual meeting of shareholders, a shareholder’s notice must be received at our principal executive offices not less than 120 calendar days or more than 150 calendar days before the date our proxy statement is released to shareholders in connection with the previous year’s annual meeting; provided however, that if the date of the meeting is changed by more than 30 days from the date of the previous year’s meeting, notice must be received no later than the close of business on the 10th day following the earlier of the day on which notice of the date of the meeting was mailed to shareholders or public disclosure of that date was made. The shareholder notice shall set forth as to each matter the shareholder proposes to bring before the meeting:

•

a brief description of and the reasons for proposing the matter at the meeting;

•

with respect to the shareholder giving notice and the beneficial owner, if any, on whose behalf the proposal is being made:

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the name and address of such person;

•

the class or series and number of shares of ONEOK which are owned beneficially and of record by such person and any affiliates or associates of such person;

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the name of each nominee holder of shares of all stock of ONEOK owned beneficially but not of record by such person or any affiliates or associates of such person, and the number of such shares of stock of ONEOK held by each such nominee holder;

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whether and the extent to which any derivative instrument, swap, option, warrant, short interest, hedge or profit interest or other transaction has been entered into by or on behalf of such person, or any affiliates or associates of such person, with respect to stock of ONEOK; and

•

whether and the extent to which any other transaction, agreement, arrangement or understanding (including any short position or any borrowing or lending of shares of stock of ONEOK) has been made by or on behalf of such person, or any affiliates or associates of such person, the effect or intent of any of the foregoing being to mitigate loss to, or to manage risk or benefit of stock price changes for, such person, or any affiliates or associates of such person, or to increase or decrease the voting power or pecuniary or economic interest of such person, or any affiliates or associates of such person, with respect to stock of ONEOK;

•

a representation that the shareholder giving notice intends to appear in person or by proxy at the annual meeting to bring such business before the meeting;

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any material interest of the shareholder of record, the beneficial owner, if any, on whose behalf the proposal is made, or any affiliate or associate of any of the foregoing, in the proposal;

•

a description of all agreements, arrangements and understandings between the shareholder, the beneficial owner, if any, on whose behalf the proposal is made or any affiliate or associate of any of the foregoing, and any other person or persons (including their names) in connection with the proposal of the business by the shareholder; and

•

all other information that would be required to be disclosed by such person as a participant in a solicitation of proxies for the election of directors in a contested election, or would be otherwise required to be disclosed in connection with such solicitation, in each case pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended.

These provisions may impede shareholders’ ability to bring matters before an annual meeting of shareholders.

Higher Vote for Some Business Combinations and Other Actions

Subject to various exceptions, including acquiring 85% of the outstanding shares less shares owned by related persons in a single transaction, a business combination (including, but not limited to, a merger or consolidation, the sale, lease, exchange, mortgage, pledge, transfer or other disposition of our assets in excess of $5,000,000, various issuances and reclassifications of securities and the adoption of a plan or proposal for liquidation or dissolution) with or upon a proposal by a related person, who is a person that is the direct or indirect beneficial owner of more than 10% of the outstanding voting shares of our stock (subject to various exceptions), and any affiliates of that person, shall require, in addition to any approvals required by law, the approval of the business combination by either:

•

a majority vote of all of the independent directors; or

•

the holders of at least 66-2/3% of the outstanding shares otherwise entitled to vote as a single class with the common stock to approve the business combination, excluding any shares owned by the related person.

In addition, our certificate of incorporation provides that our bylaws may only be adopted, amended or repealed by a majority of the board of directors or by 80% of our shareholders, voting as a class. Our certificate of incorporation also requires the affirmative vote of 80% of our shareholders to amend, repeal or adopt provisions in our certificate of incorporation relating to, among other things,

•

the number of directors and the manner of electing those directors, including the election of directors to newly created directorships;

•

provisions relating to changes in the bylaws;

•

a director’s personal liability to us or our shareholders;

•

shareholder ratification of various contracts, transactions and acts; and

•

voting requirements for approval of business combinations.

Transactions with Interested Parties

Our certificate of incorporation provides that, in the absence of fraud, no contract or other transaction will be affected or invalidated by the fact that any of our directors are in any way interested in or connected with any other party to the contract or transaction or are themselves parties to the contract or transaction, provided that the interest is fully disclosed or otherwise known to our board of directors at the meeting of the board at which the contract or transaction is authorized or confirmed, and provided further that a quorum of disinterested directors is present at the meeting of our board of directors authorizing or confirming the contract or transaction and the contract or transaction is approved by a majority of the quorum, and no interested director votes on the contract or transaction. Any contract, transaction or act entered into or taken by us or our board or any committee thereof that is ratified by a majority of a quorum of the shareholders having voting power at any annual meeting, or any special meeting called for that purpose, will be valid and binding as though ratified by all of our shareholders. Any director may vote upon any contract or other transaction between us and any subsidiary corporation without regard to the fact that he or she is also a director of that subsidiary corporation. No contract or agreement between us and any other corporation or party that owns a majority of our capital stock or any subsidiary of that other corporation shall be made or entered into without the affirmative vote of a majority of the whole board of directors at a regular meeting of the board.

Transfer Agent and Registrar

The current transfer agent and registrar for our common stock is Equiniti Trust Company, LLC (“Equiniti” or “EQ”).

DESCRIPTION OF STOCK PURCHASE CONTRACTS

AND STOCK PURCHASE CONTRACT UNITS

We may issue stock purchase contracts for the purchase of our securities or securities of an entity unaffiliated or affiliated with us, a basket of such securities or any combination of the above as specified in the applicable prospectus supplement. Each stock purchase contract will entitle the holder thereof to purchase, and obligate us to sell, on specified dates, such securities, at a specified purchase price, all as set forth in the applicable prospectus supplement. The applicable prospectus supplement will also specify the methods by which the holders may purchase such securities, any acceleration, cancellation or termination provisions or other provisions relating to the settlement of a stock purchase contract and, if applicable, the identity of any of our subsidiaries guaranteeing our obligations with respect to such stock purchase contracts. Stock purchase contracts may require holders to satisfy their obligations thereunder when the stock purchase contracts are issued. Our obligation to settle such prepaid stock purchase contracts on the relevant settlement date may constitute indebtedness. Accordingly, the prepaid stock purchase contracts will be issued under one of the Indentures. The stock purchase contracts may be issued separately or as part of a stock purchase contract unit that consists of (a) a stock purchase contract and (b) senior or subordinated debt securities, or preferred stock, U.S. Treasury securities or other debt obligations of third parties, that may be used to secure the holders’ obligations under a stock purchase contract. The stock purchase contracts may require us to make periodic payments to the holders of the stock purchase contract units, and such payments may be unsecured or prefunded on some basis. The stock purchase contracts may require holders to secure their obligations in a specified manner and, in certain circumstances, we may deliver newly issued prepaid stock purchase contracts upon release to a holder of any collateral securing such holder’s obligations under the original stock purchase contract.

The applicable prospectus supplement will describe the general terms of any stock purchase contracts or stock purchase contract units and, if applicable, prepaid stock purchase contracts. The description in the prospectus supplement will not purport to be complete and will be qualified in its entirety by reference to (a) the stock purchase contracts, (b) the collateral arrangements and depository arrangements, if applicable, relating to such stock purchase contracts or stock purchase contract units and (c) if applicable, the prepaid stock purchase contracts and the documents pursuant to which such prepaid stock purchase contracts will be issued. Some of the material United States federal income tax considerations applicable to the stock purchase contracts and the stock purchase contract units will also be discussed in the applicable prospectus supplement.

DESCRIPTION OF DEPOSITARY SHARES

General

We may, at our option, elect to offer fractional shares of preferred stock, rather than full shares of preferred stock. If we exercise this option, we will issue to the public receipts for depositary shares, and each of these depositary shares will represent a fraction (to be set forth in the applicable prospectus supplement) of a share of a particular series of preferred stock.

The shares of any series of preferred stock underlying the depositary shares will be deposited under a deposit agreement between us and a bank or trust company selected by us. The depositary will have its principal office in the United States and a combined capital of at least $50,000,000. Subject to the terms of the deposit agreement, each owner of a depositary share will be entitled, in proportion, to the applicable fraction of a share of preferred stock underlying that depositary share, to all the rights and preferences of the preferred stock underlying that depositary share. Those rights (to be set forth in the applicable prospectus supplement) include dividend, voting, redemption and liquidation rights.

The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement. Depositary receipts will be distributed to those persons purchasing the fractional shares of preferred stock underlying the depositary shares, in accordance with the terms of the offering. Copies of the forms of deposit agreement and depositary receipt will be filed as exhibits to the registration statement. The following summary of the deposit agreement, the depositary shares and the depositary receipts is not complete. You should refer to the forms of the deposit agreement and depositary receipts that will be filed with the SEC in connection with the offering of the specific depositary shares.

Pending the preparation of definitive engraved depositary receipts, the depositary may, upon our written order, issue temporary depositary receipts substantially identical to the definitive depositary receipts but not in definitive form. These temporary depositary receipts entitle their holders to all the rights of definitive depositary receipts which are to be prepared without unreasonable delay. Temporary depositary receipts will then be exchangeable for definitive depositary receipts at our expense.

Dividends and Other Distributions

The depositary will distribute all cash dividends or other cash distributions received with respect to the preferred stock to the record holders of depositary shares relating to the preferred stock in proportion to the number of depositary shares owned by those holders.

If there is a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary shares that are entitled to receive the distribution, unless the depositary determines that it is not feasible to make the distribution. If this occurs, the depositary may, with our approval, sell the property and distribute the net proceeds from the sale to the applicable holders.

Redemption of Depositary Shares

If a series of preferred stock represented by depositary shares is subject to redemption, the depositary shares will be redeemed from the proceeds received by the depositary resulting from the redemption, in whole or in part, of that series of preferred stock held by the depositary. The redemption price per depositary share will be equal to the applicable redemption fraction of the redemption price per share payable with respect to that series of the preferred stock. Whenever we redeem shares of preferred stock that are held by the depositary, the depositary will redeem, as of the same redemption date, the number of depositary shares representing the shares of preferred stock so redeemed. If fewer than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by lot or pro rata as may be determined by the depositary.

Voting the Preferred Stock

Upon receipt of notice of any meeting at which the holders of the preferred stock are entitled to vote, the depositary will mail the information contained in such notice to the record holders of the depositary shares underlying the preferred stock. Each record holder of the depositary shares on the record date, which will be the same date as the record date for the preferred stock, will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the amount of the preferred stock represented by the holder’s depositary shares. The depositary will then try, as far as practicable, to vote the number of shares of preferred stock underlying those depositary shares in accordance with such instructions. We will agree to take all actions which may be deemed necessary by the depositary to enable the depositary to do so. The depositary will not vote the shares of preferred stock to the extent it does not receive specific instructions from the holders of depositary shares underlying the preferred stock.

Amendment and Termination of the Depositary Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time be amended by agreement between us and the depositary. However, any amendment which

materially and adversely alters the rights of the holders of depositary shares will not be effective unless the amendment has been approved by the holders of at least a majority of the depositary shares then outstanding. The deposit agreement may be terminated by us or by the depositary only if (a) all outstanding depositary shares have been redeemed or (b) there has been a final distribution of the underlying preferred stock in connection with our liquidation, dissolution or winding up and the preferred stock has been distributed to the holders of depositary receipts.

Charges of Depositary

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will also pay charges of the depositary in connection with the initial deposit of the preferred stock and any redemption of the preferred stock. Holders of depositary receipts will pay other transfer and other taxes and governmental charges and those other charges, including a fee for the withdrawal of shares of preferred stock upon surrender of depositary receipts, as are expressly provided in the deposit agreement to be for their accounts.

Miscellaneous

The depositary will forward to holders of depositary receipts all reports and communications from us that we deliver to the depositary and that we are required to furnish to the holders of the preferred stock.

Neither we nor the depositary will be liable if either of us is prevented or delayed by law or any circumstance beyond our control in performing our respective obligations under the deposit agreement. Our obligations and those of the depositary will be limited to performance in good faith of our respective duties under the deposit agreement. Neither we nor the depositary will be obligated to prosecute or defend any legal proceeding in respect of any depositary shares or preferred stock unless satisfactory indemnity is furnished. We and the depositary may rely upon written advice of counsel or accountants, or upon information provided by persons presenting preferred stock for deposit, holders of depositary receipts or other persons believed to be competent and on documents believed to be genuine.

Resignation and Removal of Depositary

The depositary may resign at any time by delivering notice to us of its election to resign. We may remove the depositary at any time. Any resignation or removal will take effect upon the appointment of a successor depositary and its acceptance of the appointment. The successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50,000,000.

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of debt securities, preferred stock, common stock, or units of two or more of these types of securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any registered holders of warrants or beneficial owners of warrants.

We will distribute a prospectus supplement with regard to each issue of warrants. Each prospectus supplement will describe:

•

in the case of warrants to purchase debt securities, the designation, aggregate principal amount, currencies, denominations and terms of the series of debt securities purchasable upon exercise of the warrants and the price at which you may purchase the debt securities upon exercise;

•

in the case of warrants to purchase preferred stock, the designation, number of shares, stated value and terms, such as liquidation, dividend, conversion and voting rights, of the series of preferred stock purchasable upon exercise of the warrants and the price at which you may purchase such number of shares of preferred stock of such series upon such exercise;

•

in the case of warrants to purchase common stock, the number of shares of common stock purchasable upon the exercise of the warrants and the price at which you may purchase such number of shares of common stock upon such exercise;

•

the period during which you may exercise the warrants;

•

any provision adjusting the securities that may be purchased on exercise of the warrants, and the exercise price of the warrants, to prevent dilution or otherwise;

•

the place or places where warrants can be presented for exercise or for registration of transfer or exchange; and

•

any other material terms of the warrants.

Warrants for the purchase of preferred stock and common stock will be offered and exercisable for U.S. dollars only. Warrants will be issued in registered form only. The exercise price for warrants will be subject to adjustment as described in the applicable prospectus supplement.

Prior to the exercise of any warrants to purchase debt securities, preferred stock or common stock, holders of the warrants will not have any of the rights of holders of the debt securities, preferred stock or common stock purchasable upon exercise, including:

•

in the case of warrants for the purchase of debt securities, the right to receive payments of principal of, any premium or interest on the debt securities purchasable upon exercise or to enforce covenants in the applicable indenture; or

•

in the case of warrants for the purchase of preferred stock or common stock, the right to vote or to receive any payments of dividends on the preferred stock or common stock purchasable upon exercise.

PLAN OF DISTRIBUTION

We will set forth in the applicable prospectus supplement a description of the plan of distribution of our securities that may be offered pursuant to this prospectus.

LEGAL MATTERS

The validity of the securities being offered hereby will be passed upon for us by GableGotwals, Tulsa, Oklahoma, except that Latham & Watkins LLP, Austin, Texas, will pass upon such matters to the extent governed by New York law.

EXPERTS

The financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2025 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

PART II.

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution (Estimated).

The following table sets forth the expenses in connection with the issuance and distribution of the securities being registered, other than underwriting discounts and commissions. All of the amounts shown are estimated, except the SEC registration fee.


SEC registration fee	$	*
Legal fees and expenses		**
Printing and engraving		**
Accounting fees and expenses		**
Trustee fees and expenses		**
Rating agencies fees		**
Blue sky fees and expenses		**
Miscellaneous		**

	$	**

*	Deferred in accordance with Rule 456(b) of the Securities Act, as amended, and calculated in accordance with the offering of securities under this registration statement pursuant to Rule 457(r) of the Securities Act, as amended.

**	The amount of these expenses is not presently known.

Item 15. Indemnification of Directors and Officers.

ONEOK is empowered by Section 1031 of the Oklahoma General Corporation Act, subject to the procedures and limitations stated therein, to indemnify any person against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with any threatened, pending or completed action, suit or proceeding (whether civil, criminal, administrative or investigative) in which such person is made or threatened to be made a party by reason of such person being or having been a director, officer, employee or agent of ONEOK or is or was serving at its request as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, if such person acted in good faith and in a manner such person reasonably believed to be in or not opposed to the best interests of ONEOK, and with respect to any criminal action or proceeding, had no reasonable cause to believe such person’s conduct was unlawful. However, in an action by or in the right of ONEOK, Section 1031 prohibits indemnification if such person is adjudged to be liable to ONEOK, unless such indemnification is allowed by a court of competent jurisdiction. The statute provides that indemnification pursuant to its provisions is not exclusive of other rights of indemnification to which a person may be entitled under any bylaw, agreement, vote of shareholders, or disinterested directors, or otherwise.

The certificate of incorporation of ONEOK provides that a director of the corporation shall not be personally liable to the corporation or its shareholders for monetary damages for breach of fiduciary duty as a director, except for liability for (i) any breach of the director’s duty of loyalty to the corporation or its shareholders, (ii) acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) payment of unlawful dividends or unlawful stock purchases or redemptions or (iv) any transaction from which the director derived an improper personal benefit.

Article VIII of ONEOK’s bylaws provides that directors and officers of ONEOK shall be indemnified by ONEOK to the fullest extent permitted by the Oklahoma General Corporation Act, including the advance of related expenses. Pursuant to Article VIII of the bylaws of ONEOK, upon authorization and determination (i) by

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the board of directors by a majority vote of the directors who were not parties to such action, suit or proceeding, even though less than a quorum; (ii) by a committee of directors designated by a majority vote of directors, even though less than a quorum; (iii) if there are no such directors, or if such directors so direct, by independent legal counsel in a written opinion; or (iv) by the shareholders, ONEOK is obligated to indemnify any person who incurs liability by reason of the fact that such person is or was a director, officer, employee or agent of ONEOK, or is or was serving at the request of ONEOK as a director, officer, employee or agent of another corporation, partnership, limited liability company, joint venture, trust or other enterprise or as a member of any committee or similar body, if the person acted in good faith and in a manner the person reasonably believed to be in or not opposed to the best interests of ONEOK, and, with respect to any criminal action or proceeding, had no reasonable cause to believe the person’s conduct was unlawful. However, in an action, suit or proceeding by or in the right of ONEOK, no indemnification will be made if such person shall be adjudged to be liable to ONEOK, unless such indemnification is allowed by a court of competent jurisdiction.

ONEOK has entered into indemnification agreements with its directors and officers. These indemnification agreements provide that ONEOK is obligated to indemnify the specified director or officer to the fullest extent permitted by law. The agreements provide that, upon request by a director or officer, ONEOK is obligated to advance expenses for defense of a claim made against the director or officer. The obligation of ONEOK to indemnify the director or officer is subject to applicable law and (a) the determination by an independent counsel if requested by the indemnitee or (b) if an indemnitee does not make such a request, the determination by (1) a majority vote of the disinterested directors, even though less than a quorum, (2) a committee of disinterested directors designated by a majority vote of the disinterested directors, even though less than a quorum, (3) an independent counsel in a written opinion to the board of directors if there are no disinterested directors, or if the board so directs, or (4) ONEOK’s shareholders holding a majority of the outstanding common stock. In addition, the agreements obligate ONEOK to indemnify the specified officer or director to the extent of ONEOK’s recoveries under insurance policies regardless of whether the director or officer is ultimately determined to be entitled to indemnification. The agreements also provide for partial indemnification if a portion of a claim for indemnification is not allowed by the reviewing party appointed by the board of directors.

ONEOK provides liability insurance for its directors and officers which provides for coverage against loss from claims made against officers and directors in their capacity as such, including, subject to certain exceptions, liabilities under the federal securities laws.

It is recognized that the above-summarized provisions of ONEOK’s bylaws, the indemnification agreements and the applicable provisions of the Oklahoma General Corporation Act may be sufficiently broad to indemnify officers, directors and controlling persons of ONEOK against liabilities arising under such act.

Item 16. Exhibits.


Exhibit Number		Description
1.1*		Form of Underwriting Agreement.

3.1†		Amended and Restated Certificate of Incorporation of ONEOK, Inc., dated April 28, 2025, as amended.

3.2		Amended and Restated By-laws of ONEOK, Inc. (incorporated by reference to Exhibit 3.1 to ONEOK, Inc.’s Current Report on Form 8-K filed on February 24, 2023).

4.1		Indenture, dated September 24, 1998, between ONEOK, Inc. and Chase Bank of Texas (incorporated by reference from Exhibit 4.1 to Registration Statement on Form S-3 filed August 26, 1998 (File No. 1-13643)).

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4.2		Second Supplemental Indenture, dated as of September 25, 1998, between ONEOK, Inc. and Chase Bank of Texas, as trustee, with respect to the 6.875% Debentures due 2028 (incorporated by reference from Exhibit 5(b) to ONEOK, Inc.’s Current Report on Form 8-K/A filed October 2, 1998 (File No. 1-13643)).

4.3		Fifth Supplemental Indenture, dated as of June 30, 2017, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and The Bank of New York Mellon Trust, as trustee (incorporated by reference from Exhibit 4.1 to ONEOK, Inc.’s Current Report on Form 8-K filed July 3, 2017 (File No. 1-13643)).

4.4		Sixth Supplemental Indenture, dated as of September 25, 2023, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and The Bank of New York Mellon Trust, as trustee (incorporated by reference from Exhibit 4.1 to ONEOK, Inc.’s Current Report on Form 8-K filed September 25, 2023 (File No. 1-13643)).

4.5		Seventh Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., EnLink Midstream Partners, LP, Elk Merger Sub II, L.L.C. and The Bank of New York Mellon Trust Company, National Association, as trustee (incorporated by reference to Exhibit 4.10 to ONEOK, Inc.’s Current Report on Form 8-K filed Feb. 5, 2025 (File No. 1-13643)).

4.6		Indenture, dated as of Dec. 28, 2001, between ONEOK, Inc. and SunTrust Bank, as trustee (incorporated by reference from Exhibit 4.1 to Amendment No. 1 to ONEOK, Inc.’s Registration Statement on Form S-3 filed Dec. 28, 2001 (File No. 333-65392)).

4.7		Third Supplemental Indenture, dated as of June 17, 2005, between ONEOK, Inc. and SunTrust Bank, as trustee, with respect to the 6.00% Senior Notes due 2035 (incorporated by reference from Exhibit 4.3 to ONEOK, Inc.’s Current Report on Form 8-K filed June 17, 2005 (File No. 1-13643)).

4.8		Fourth Supplemental Indenture, dated as of June 30, 2017, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 6.00% Senior Notes due 2035 (incorporated by reference from Exhibit 4.3 to ONEOK, Inc.’s Current Report on Form 8-K filed July 3, 2017 (File No. 1-13643)).

4.9		Fifth Supplemental Indenture, dated as of September 25, 2023, among ONEOK, Inc., as issuer, ONEOK Partners, L.P., as guarantor, ONEOK Partners Intermediate Limited Partnership, as guarantor, and Magellan Midstream Partners, L.P., as guarantor, U.S. Bank Trust Company, National Association, as trustee (incorporated by reference from Exhibit 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed September 25, 2023 (File No. 1-13643)).

4.10		Sixth Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., EnLink Midstream Partners, LP, Elk Merger Sub II, L.L.C. and U.S. Bank Trust Company, National Association, as trustee (incorporated by reference to Exhibit 4.13 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.11		Indenture, dated as of Sept. 25, 2006, between ONEOK Partners, L.P. and Wells Fargo Bank, N.A., as trustee (incorporated by reference to Exhibit 4.1 to ONEOK Partners, L.P.’s Current Report on Form 8-K filed Sept. 26, 2006 (File No. 1-12202)).

4.12		Third Supplemental Indenture, dated as of Sept. 25, 2006, among ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and Wells Fargo Bank, N.A., as trustee, with respect to the 6.65% Senior Notes due 2036 (incorporated by reference to Exhibit 4.4 to ONEOK Partners, L.P.’s Current Report on Form 8-K filed Sept. 26, 2006 (File No. 1-12202)).

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4.13		Fourth Supplemental Indenture, dated as of Sept. 28, 2007, among ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and Wells Fargo Bank, N.A., as trustee, with respect to the 6.85% Senior Notes due 2037 (incorporated by reference to Exhibit 4.2 to ONEOK Partners, L.P.’s Current Report on Form 8-K filed Sept. 28, 2007 (File No. 1-12202)).

4.14		Seventh Supplemental Indenture, dated as of Jan. 26, 2011, among ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and Wells Fargo Bank, N.A., as trustee, with respect to the 6.125% Senior Notes due 2041 (incorporated by reference from Exhibit 4.3 to ONEOK Partners, L.P.’s Current Report on Form 8-K filed Jan. 26, 2011 (File No. 1-12202)).

4.15		Twelfth Supplemental Indenture, dated as of Sept. 12, 2013, among ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and Wells Fargo Bank, N.A., as trustee, with respect to the 6.200% Senior Notes due 2043 (incorporated by reference to Exhibit 4.4 to ONEOK Partners, L.P.’s Current Report on Form 8-K filed Sept. 12, 2013 (File No. 1-12202)).

4.16		Fifteenth Supplemental Indenture, dated as of June 30, 2017, by and among ONEOK Partners, L.P., ONEOK, Inc., ONEOK Partners Intermediate Limited Partnership and Wells Fargo Bank, N.A., as trustee (incorporated by reference from Exhibit 4.1 to ONEOK Partners, L.P.’s Current Report on Form 8-K filed July 3, 2017 (File No. 1-12202)).

4.17		Sixteenth Supplemental Indenture, dated as of Sept. 25, 2023, among ONEOK Partners, L.P., ONEOK, Inc., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and Computershare Trust Company, N.A., as trustee (incorporated by reference from Exhibit 4.4 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 25, 2023 (File No. 1-13643)).

4.18		Seventeenth Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, ONEOK, Inc., Magellan Midstream Partners, L.P., EnLink Midstream Partners, LP, Elk Merger Sub II, L.L.C., and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.15 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.19		Indenture, dated as of Jan. 26, 2012, among ONEOK, Inc. and U.S. Bank National Association, as trustee (incorporated by reference to Exhibit 4.1 to ONEOK, Inc.’s Current Report on Form 8-K filed Jan. 26, 2012 (File No. 1-13643)).

4.20		Fourth Supplemental Indenture, dated as of July 13, 2017, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 4.00% Senior Notes due 2027 (incorporated by reference from Exhibit 4.1 to ONEOK, Inc.’s Current Report on Form 8-K filed July 13, 2017 (File No. 1-13643)).

4.21		Fifth Supplemental Indenture, dated as of July 13, 2017, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 4.95% Senior Notes due 2047 (incorporated by reference from Exhibit 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed July 13, 2017 (File No. 1-13643)).

4.22		Sixth Supplemental Indenture, dated as of July 2, 2018, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 4.55% Senior Notes due 2028 (incorporated by reference from Exhibit No. 4.1 to ONEOK, Inc.’s Current Report on Form 8-K filed July 2, 2018 (File No. 1-13643)).

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4.23		Seventh Supplemental Indenture, dated as of July 2, 2018, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 5.20% Senior Notes due 2048 (incorporated by reference from Exhibit No. 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed July 2, 2018 (File No. 1-13643)).

4.24		Eighth Supplemental Indenture, dated as of March 13, 2019, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 4.35% Senior Notes due 2029 (incorporated by reference from Exhibit No. 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed March 13, 2019 (File No. 1-13643)).

4.25		Ninth Supplemental Indenture, dated March 13, 2019, among ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and Wells Fargo Bank, N.A., as trustee, with respect to the 5.20% Senior Notes due 2048 (incorporated by reference from Exhibit 4.3 to ONEOK Partners, L.P.’s Current Report on Form 8-K filed March 13, 2019 (File No. 1-12202)).

4.26		Eleventh Supplemental Indenture, dated as of Aug. 15, 2019, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 3.40% Senior Notes due 2029 (incorporated by reference from Exhibit No. 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed Aug. 15, 2019 (File No. 1-13643)).

4.27		Twelfth Supplemental Indenture, dated as of Aug. 15, 2019, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 4.45% Senior Notes due 2049 (incorporated by reference from Exhibit No. 4.3 to ONEOK, Inc.’s Current Report on Form 8-K filed Aug. 15, 2019 (File No. 1-13643)).

4.28		Fourteenth Supplemental Indenture, dated as of March 10, 2020, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 3.100% Senior Notes due 2030 (incorporated by reference from Exhibit No. 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed March 10, 2020 (File No. 1-13643)).

4.29		Fifteenth Indenture, dated as of March 10, 2020, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 4.500% Senior Notes due 2050 (incorporated by reference from Exhibit No. 4.3 to ONEOK, Inc.’s Current Report on Form 8-K filed March 20, 2020 (File No. 1-13643)).

4.30		Seventeenth Supplemental Indenture, dated as of May 7, 2020, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 6.350% Senior Notes due 2031 (incorporated by reference from Exhibit No. 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed May 7, 2020 (File No. 1-13643)).

4.31		Eighteenth Supplemental Indenture, dated as of May 7, 2020, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 7.150% Senior Notes due 2051 (incorporated by reference from Exhibit No. 4.3 to ONEOK, Inc.’s Current Report on Form 8-K filed May 7, 2020 (File No. 1-13643)).

4.32		Nineteenth Supplemental Indenture, dated as of Nov. 18, 2022, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank Trust Company, National Association (successor in interest to U.S. Bank National Association), as trustee, with respect to the 6.100% Senior Notes due 2032 (incorporated by reference from Exhibit No. 4.1 to ONEOK, Inc.’s Current Report on Form 8-K filed Nov. 18, 2022 (File No. 1-13643)).

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4.33		Twentieth Supplemental Indenture, dated as of Aug. 24, 2023, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 5.550% Senior Notes due 2026 (incorporated by reference from Exhibit 4.1 to ONEOK, Inc.’s Current Report on Form 8-K, filed Aug. 25, 2023 (File No. 1-13643)).

4.34		Twenty-First Supplemental Indenture, dated as of Aug. 24, 2023, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 5.650% Senior Notes due 2028 (incorporated by reference from Exhibit 4.2 to ONEOK, Inc.’s Current Report on Form 8-K, filed Aug. 25, 2023 (File No. 1-13643)).

4.35		Twenty-Second Supplemental Indenture, dated as of Aug. 24, 2023, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 5.800% Senior Notes due 2030 (incorporated by reference from Exhibit 4.3 to ONEOK, Inc.’s Current Report on Form 8-K, filed Aug. 25, 2023 (File No. 1-13643)).

4.36		Twenty-Third Supplemental Indenture, dated as of Aug. 24, 2023, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 6.050% Senior Notes due 2033 (incorporated by reference from Exhibit 4.4 to ONEOK, Inc.’s Current Report on Form 8-K, filed Aug. 25, 2023 (File No. 1-13643)).

4.37		Twenty-Fourth Supplemental Indenture, dated as of Aug. 24, 2023, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank National Association, as trustee, with respect to the 6.625% Senior Notes due 2053 (incorporated by reference from Exhibit 4.5 to ONEOK, Inc.’s Current Report on Form 8-K, filed Aug. 25, 2023 (File No. 1-13643)).

4.38		Twenty-Fifth Supplemental Indenture, dated as of Sept. 25, 2023, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee (incorporated by reference from Exhibit 4.3 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 25, 2023 (File No. 1-13643)).

4.39		Twenty-Sixth Supplemental Indenture, dated as of Sept. 24, 2024, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee, with respect to 4.250% Notes due 2027 (incorporated by reference from Exhibit 4.2 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 24, 2024 (File No. 1-13643)).

4.40		Twenty-Seventh Supplemental Indenture, dated as of Sept. 24, 2024, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee, with respect to 4.400% Notes due 2029 (incorporated by reference from Exhibit 4.3 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 24, 2024 (File No. 1-13643)).

4.41		Twenty-Eighth Supplemental Indenture, dated as of Sept. 24, 2024, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee, with respect to 4.750% Notes due 2031 (incorporated by reference from Exhibit 4.4 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 24, 2024 (File No. 1-13643)).

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4.42		Twenty-Ninth Supplemental Indenture, dated as of Sept. 24, 2024, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee, with respect to 5.050% Notes due 2034 (incorporated by reference from Exhibit 4.5 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 24, 2024 (File No. 1-13643)).

4.43		Thirtieth Supplemental Indenture, dated as of Sept. 24, 2024, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee, with respect to 5.700% Notes due 2054 (incorporated by reference from Exhibit 4.6 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 24, 2024 (File No. 1-13643)).

4.44		Thirty-First Supplemental Indenture, dated as of Sept. 24, 2024, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee, with respect to 5.850% Notes due 2064 (incorporated by reference from Exhibit 4.7 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 24, 2024 (File No. 1-13643)).

4.45		Thirty-Second Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., EnLink Midstream Partners, LP, Elk Merger Sub II, L.L.C. and U.S. Bank Trust Company, National Association, as trustee (incorporated by reference to Exhibit 4.14 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.46		Thirty-Third Supplemental Indenture, dated as of August 12, 2025, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., Elk Merger Sub II, L.L.C., EnLink Midstream Partners, LP and U.S. Bank National Association, as trustee, with respect to 4.950% Notes due 2032 (incorporated by reference from Exhibit 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed August 13, 2025 (File No. 1-13643)).

4.47		Thirty-Fourth Supplemental Indenture, dated as of August 12, 2025, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., Elk Merger Sub II, L.L.C., EnLink Midstream Partners, LP and U.S. Bank National Association, as trustee, with respect to 5.400% Notes due 2035 (incorporated by reference from Exhibit 4.3 to ONEOK, Inc.’s Current Report on Form 8-K filed August 13, 2025 (File No. 1-13643)).

4.48		Thirty-Fifth Supplemental Indenture, dated as of August 12, 2025, among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., Elk Merger Sub II, L.L.C., EnLink Midstream Partners, LP and U.S. Bank National Association, as trustee, with respect to 6.250% Notes due 2055 (incorporated by reference from Exhibit 4.4 to ONEOK, Inc.’s Current Report on Form 8-K filed August 13, 2025 (File No. 1-13643)).

4.49		Indenture, dated as of April 19, 2007, between Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee (incorporated by reference from Exhibit 4.1 to Magellan Midstream Partners, L.P.’s Form 8-K, filed April 20, 2007 (File No. 1-16335)).

4.50		First Supplemental Indenture, dated as of April 19, 2007, between Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee, with respect to the 6.400% Senior Notes due 2037 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Form 8-K, filed April 20, 2007 (File No. 1-16335)).

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4.51		Second Supplemental Indenture, dated as of Sept. 25, 2023, among Magellan Midstream Partners, L.P., ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank Trust Company, National Association, as trustee (incorporated by reference from Exhibit 4.5 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 25, 2023 (File No. 1-13643)).

4.52		Third Supplemental Indenture, dated as of Dec. 13, 2023, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank Trust Company, National Association, as trustee (incorporated by reference from Exhibit 4.1 to ONEOK, Inc.’s Current Report on Form 8-K filed Dec. 14, 2023 (File No. 1-13643)).

4.53		Fourth Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., EnLink Midstream Partners, LP, Elk Merger Sub II, L.L.C., and U.S. Bank Trust Company, National Association, as trustee (incorporated by reference to Exhibit 4.12 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.54		Indenture, dated as of Aug. 11, 2010, between Magellan Midstream Partners, L.P. and U.S. Bank National Association, as trustee (incorporated by reference from Exhibit 4.1 to Midstream Partners, L.P.’s Form 8-K, filed Aug. 16, 2010 (File No. 1-16335)).

4.55		Second Supplemental Indenture, dated as of Nov. 9, 2012, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 4.200% Senior Notes due 2042 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed Nov. 9, 2012 (File No. 1-16335)).

4.56		Third Supplemental Indenture, dated as of Oct. 10, 2013, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 5.15% Senior Notes due 2043 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed Oct. 10, 2013 (File No. 1-16335)).

4.57		Fifth Supplemental Indenture, dated as of March 4, 2015, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 4.20% Senior Notes due 2045 (incorporated by reference from Exhibit 4.3 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed March 4, 2015 (File No. 1-16335)).

4.58		Seventh Supplemental Indenture, dated as of Sept. 13, 2016, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 4.25% Senior Notes due 2046 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed Sept. 13, 2016 (File No. 1-16335)).

4.59		Eighth Supplemental Indenture, dated as of Oct. 3, 2017, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 4.200% Senior Notes due 2047 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed Oct. 3, 2017 (File No. 1-16335)).

4.60		Ninth Supplemental Indenture, dated as of Jan. 18, 2019, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 4.850% Senior Notes due 2049 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed Jan. 18, 2019 (File No. 1-16335)).

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4.61		Tenth Supplemental Indenture, dated as of Aug. 19, 2019, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 3.950% Senior Notes due 2050 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed Aug. 19, 2019 (File No. 1-16335)).

4.62		Eleventh Supplemental Indenture, dated as of May 20, 2020, between ONEOK, Inc. (successor in interest to Magellan Midstream Partners, L.P.), and U.S. Bank National Association, as trustee, with respect to the 3.250% Senior Notes due 2030 (incorporated by reference from Exhibit 4.2 to Magellan Midstream Partners, L.P.’s Current Report on Form 8-K, filed May 20, 2020 (File No. 1-16335))

4.63		Twelfth Supplemental Indenture, dated as of Sept. 25, 2023, among Magellan Midstream Partners, L.P., ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership and U.S. Bank Trust Company, National Association, as trustee (incorporated by reference from Exhibit 4.6 to ONEOK, Inc.’s Current Report on Form 8-K, filed Sept. 25, 2023 (File No. 1-13643)).

4.64		Thirteenth Supplemental Indenture, dated as of Dec. 13, 2023, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and U.S. Bank Trust Company, National Association, as trustee, (incorporated by reference from Exhibit 4.2 to ONEOK, Inc.’s Current Report on Form 8-K filed Dec. 14, 2023 (File No. 1-13643)).

4.65		Fourteenth Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P., EnLink Midstream Partners, LP, Elk Merger Sub II, L.L.C., and U.S. Bank Trust Company, National Association, as trustee (incorporated by reference to Exhibit 4.11 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.66		Indenture, dated as of March 19, 2014, by and between EnLink Midstream Partners, LP and Wells Fargo Bank, National Association, as trustee (incorporated by reference to Exhibit 4.2 to EnLink Midstream Partners, LP’s Current Report on Form 8-K, filed March 21, 2014 (File No. 001-36340)).

4.67		First Supplemental Indenture, dated as of March 19, 2014, by and between EnLink Midstream Partners, LP and Wells Fargo Bank, National Association, as trustee (incorporated by reference to Exhibit 4.3 to EnLink Midstream Partners, LP’s Current Report on Form 8-K, filed March 21, 2014 (File No. 001-36340)).

4.68		Second Supplemental Indenture, dated as of Nov. 12, 2014, by and between EnLink Midstream Partners, LP and Wells Fargo Bank, National Association, as trustee (incorporated by reference to Exhibit 4.3 to EnLink Midstream Partners, LP’s Current Report on Form 8-K, filed Nov. 12, 2014 (File No. 001-36340)).

4.69		Fifth Supplemental Indenture, dated as of May 11, 2017, by and between EnLink Midstream Partners, LP and Wells Fargo Bank, National Association, as trustee (incorporated by reference to Exhibit 4.2 to EnLink Midstream Partners, LP’s Current Report on Form 8-K, filed May 11, 2017 (File No. 001-36340)).

4.70		Sixth Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., EnLink Midstream Partners, LP, Elk Merger Sub II, L.L.C., ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.9 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.71		Indenture, dated as of April 9, 2019, by and between EnLink Midstream, LLC and Wells Fargo Bank, National Association, as trustee (incorporated by reference to Exhibit 4.1 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed April 9, 2019 (File No. 001-36336)).

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4.72		First Supplemental Indenture, dated as of April 9, 2019, by and among EnLink Midstream, LLC, EnLink Midstream Partners, LP, and Wells Fargo Bank, National Association, as trustee (incorporated by reference to Exhibit 4.2 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed April 9, 2019 (File No. 001-36336)).

4.73		Second Supplemental Indenture, dated as of January 31, 2025, by and among Elk Merger Sub II, L.L.C., as issuer, EnLink Midstream Partners, LP, as guarantor, and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.2 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed Jan. 31, 2025, File No. 001-36336).

4.74		Third Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., Elk Merger Sub II, L.L.C., EnLink Midstream Partners, LP, ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.5 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.75		Indenture, dated as of Dec. 17, 2020, by and among EnLink Midstream, LLC, as issuer, EnLink Midstream Partners, LP, as guarantor, and Wells Fargo Bank, National Association, as trustee (incorporated by reference to Exhibit 4.1 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed Dec. 18, 2020 (File No. 001-36336)).

4.76		First Supplemental Indenture, dated as of Jan. 31, 2025, by and among Elk Merger Sub II, L.L.C., as issuer, EnLink Midstream Partners, LP, as guarantor, and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.1 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed Jan. 31, 2025, File No. 001-36336).

4.77		Second Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., Elk Merger Sub II, L.L.C., EnLink Midstream Partners, LP, ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.6 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.78		Indenture, dated as of Aug. 31, 2022, by and among EnLink Midstream, LLC, as issuer, EnLink Midstream Partners, LP, as guarantor, and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.1 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed on Aug. 31, 2022 (File No. 001-36336)).

4.79		First Supplemental Indenture, dated as of Jan. 31, 2025, by and among Elk Merger Sub II, L.L.C., as issuer, EnLink Midstream Partners, LP, as guarantor, and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.3 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed Jan. 31, 2025, File No. 001-36336).

4.80		Second Supplemental Indenture, dated as of Jan. 31, 2025, by and among ONEOK, Inc., Elk Merger Sub II, L.L.C., EnLink Midstream Partners, LP, ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.7 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.81		Indenture, dated as of Aug. 15, 2024, by and among EnLink Midstream, LLC, as issuer, EnLink Midstream Partners, LP, as guarantor, and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.1 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed Aug. 15, 2024 (File No. 001-36336)).

4.82		First Supplemental Indenture, dated as of August 15, 2024, by and among EnLink Midstream, LLC, as issuer, EnLink Midstream Partners, LP, as guarantor, and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.2 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed Aug. 15, 2024 (File No. 001-36336)).

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4.83		Second Supplemental Indenture, dated as of January 31, 2025, by and among Elk Merger Sub II, L.L.C., as issuer, EnLink Midstream Partners, LP, as guarantor, and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.4 to EnLink Midstream, LLC’s Current Report on Form 8-K, filed Jan. 31, 2025, File No. 001-36336).

4.84		Third Supplemental Indenture, dated as of January 31, 2025, by and among ONEOK, Inc., Elk Merger Sub II, L.L.C., EnLink Midstream Partners, LP, ONEOK Partners, L.P., ONEOK Partners Intermediate Limited Partnership, Magellan Midstream Partners, L.P. and Computershare Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.8 to ONEOK, Inc.’s Current Report on Form 8-K, filed Feb. 5, 2025 (File No. 1-13643)).

4.85†		Form of Senior Indenture.

4.86†		Form of Subordinated Indenture.

4.87*		Form of Senior Debt Security.

4.88*		Form of Subordinated Debt Security.

4.89*		Form of Certificate of Designation.

4.90*		Form of Stock Purchase Contract Agreement.

4.91*		Form of Stock Purchase Contract Unit Certificate.

4.92*		Form of Warrant Agreement.

4.93*		Form of Warrant Certificate.

4.94*		Form of Depositary Agreement.

4.95*		Form of Depositary Receipt.

5.1†		Opinion of Latham & Watkins LLP.

5.2†		Opinion of GableGotwals.

23.1†		Consent of PricewaterhouseCoopers LLP.

23.2†		Consent of Latham & Watkins LLP (contained in Exhibit 5.1).

23.3†		Consent of GableGotwals (contained in Exhibit 5.2).

24.1†		Powers of Attorney (included on the signature page of this registration statement).

25.1†		Statement of Eligibility of the Trustee under the Trust Indenture Act of 1939 on Form T-1 with respect to the Senior Indenture.

25.2†		Statement of Eligibility of the Trustee under the Trust Indenture Act of 1939 on Form T-1 with respect to the Subordinated Indenture.

107†		Filing Fee Table

*	To be filed by amendment or as an exhibit to a current report on Form 8-K and incorporated herein by reference.

†	Filed herewith.

Item 17. Undertakings.

Each of the undersigned co-registrants hereby undertakes:

(a)

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i)

to include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

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(ii)

to reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii)

to include any material information with respect to the plan of distribution not previously disclosed in this registration statement or any material change to such information in this registration statement;

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in this registration statement or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act to any purchaser:

(i)

Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii)

Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which the prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for the purpose of determining liability of the registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of

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securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i)

Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii)

Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by such undersigned registrant;

(iii)

The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv)

Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

(d) The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of the Trust Indenture Act.

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SIGNATURE

Pursuant to the requirements of the Securities Act, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Tulsa, State of Oklahoma, on the 18th day of June, 2026.


ONEOK, INC.

By:		/s/ Walter S. Hulse III
		Walter S. Hulse III
		Chief Financial Officer, Treasurer and Executive Vice President,
		Corporate Development and Investor Relations

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears immediately below constitutes and appoints Walter S. Hulse III and Sarah M. Rechter, and each of them, his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement, and registration statements filed pursuant to Rule 462 under the Securities Act, and to file the same with all exhibits thereto and other documents in connection therewith, with the SEC, granting unto said attorney-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agents or any of them, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated and on the 18th day of June, 2026.


Signature		Title

/s/ Julie H. Edwards Julie H. Edwards		Board Chair

/s/ Pierce H. Norton II Pierce H. Norton II		President, Chief Executive Officer and Director (Principal Executive Officer)

/s/ Walter S. Hulse III Walter S. Hulse III		Chief Financial Officer, Treasurer, and Executive Vice President, Corporate Development and Investor Relations (Principal Financial Officer)

/s/ Mary M. Spears Mary M. Spears		Senior Vice President and Chief Accounting Officer, Finance and Tax (Principal Accounting Officer)

/s/ Brian L. Derksen Brian L. Derksen		Director

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Signature		Title

/s/ Lori A. Gobillot Lori A. Gobillot		Director

/s/ Mark W. Helderman Mark W. Helderman		Director

/s/ Randall J. Larson Randall J. Larson		Director

/s/ Mark A. McCollum Mark A. McCollum		Director

/s/ Precious Williams Owodunni Precious Williams Owodunni		Director

/s/ Eduardo A. Rodriguez Eduardo A. Rodriguez		Director

/s/ Wayne T. Smith Wayne T. Smith		Director

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SIGNATURE


ONEOK PARTNERS, L.P.

By: ONEOK Partners GP, L.L.C.
		its general partner

By:		/s/ Walter S. Hulse III
		Walter S. Hulse III
		Chief Financial Officer, Treasurer and
		Executive Vice President,
		Investor Relations and Corporate Development

POWER OF ATTORNEY

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated and on the 18th day of June, 2026.


Signature		Title
		(of ONEOK Partners GP, L.L.C.)

/s/ Pierce H. Norton II Pierce H. Norton II		President, Chief Executive Officer and Director (Principal Executive Officer)

/s/ Walter S. Hulse III Walter S. Hulse III		Chief Financial Officer, Treasurer and Executive Vice President, Investor Relations and Corporate Development (Principal Financial Officer)

/s/ Mary M. Spears Mary M. Spears		Senior Vice President and Chief Accounting Officer, Finance and Tax (Principal Accounting Officer)

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SIGNATURE


ONEOK PARTNERS INTERMEDIATE LIMITED PARTNERSHIP

By: ONEOK ILP GP, L.L.C.,
		its general partner

By:		/s/ Walter S. Hulse III
		Walter S. Hulse III
		Chief Financial Officer, Treasurer and
		Executive Vice President,
		Investor Relations and Corporate Development

POWER OF ATTORNEY

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated and on the 18th day of June, 2026.


Signature		Title
		(of ONEOK ILP GP, L.L.C.)

/s/ Pierce H. Norton II Pierce H. Norton II		President, Chief Executive Officer and Director (Principal Executive Officer)

/s/ Walter S. Hulse III Walter S. Hulse III		Chief Financial Officer, Treasurer and Executive Vice President, Investor Relations and Corporate Development (Principal Financial Officer)

/s/ Mary M. Spears Mary M. Spears		Senior Vice President and Chief Accounting Officer, Finance and Tax (Principal Accounting Officer)

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SIGNATURE


MAGELLAN MIDSTREAM PARTNERS, L.P.

By: MAGELLAN GP, LLC,
		its general partner

By:		/s/ Walter S. Hulse III
		Walter S. Hulse III
		Chief Financial Officer, Treasurer and
		Executive Vice President,
		Investor Relations and Corporate Development

POWER OF ATTORNEY

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated and on the 18th day of June, 2026.


Signature		Title
		(of Magellan GP, LLC)

/s/ Pierce H. Norton II Pierce H. Norton II		President, Chief Executive Officer and Director (Principal Executive Officer)

/s/ Walter S. Hulse III Walter S. Hulse III		Chief Financial Officer, Treasurer and Executive Vice President, Investor Relations and Corporate Development (Principal Financial Officer)

/s/ Mary M. Spears Mary M. Spears		Senior Vice President and Chief Accounting Officer, Finance and Tax (Principal Accounting Officer)

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SIGNATURE


ELK MERGER SUB II, L.L.C.

By:		/s/ Walter S. Hulse III
		Walter S. Hulse III
		Chief Financial Officer, Treasurer and
		Executive Vice President,
		Investor Relations and Corporate Development

POWER OF ATTORNEY

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated and on the 18th day of June, 2026.


Signature		Title
		(of Elk Merger Sub II, L.L.C.)

/s/ Pierce H. Norton II Pierce H. Norton II		President, Chief Executive Officer and Director (Principal Executive Officer)

/s/ Walter S. Hulse III Walter S. Hulse III		Chief Financial Officer, Treasurer and Executive Vice President, Investor Relations and Corporate Development (Principal Financial Officer)

/s/ Mary M. Spears Mary M. Spears		Senior Vice President and Chief Accounting Officer, Finance and Tax (Principal Accounting Officer)

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SIGNATURE


ENLINK MIDSTREAM PARTNERS, LP

By: ENLINK MIDSTREAM GP, LLC
		its general partner

By:		/s/ Walter S. Hulse III
		Walter S. Hulse III
		Chief Financial Officer, Treasurer and
		Executive Vice President,
		Investor Relations and Corporate Development

POWER OF ATTORNEY

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated and on the 18th day of June, 2026.


Signature		Title
		(of EnLink Midstream GP, LLC)

/s/ Pierce H. Norton II Pierce H. Norton II		President, Chief Executive Officer and Director (Principal Executive Officer)

/s/ Walter S. Hulse III Walter S. Hulse III		Chief Financial Officer, Treasurer and Executive Vice President, Investor Relations and Corporate Development (Principal Financial Officer)

/s/ Mary M. Spears Mary M. Spears		Senior Vice President and Chief Accounting Officer, Finance and Tax (Principal Accounting Officer)

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SEC Form S-3ASR filed by ONEOK Inc.