SEC Form 6-K filed by TIM S.A.

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16
UNDER THE SECURITIES EXCHANGE ACT OF 1934

Date of Report: November 3, 2025

Commission File Number: 001-39570

TIM S.A.
(Exact name of Registrant as specified in its Charter)

João Cabral de Melo Neto Avenue, 850 – North Tower – 12^th floor
22775-057 Rio de Janeiro, RJ, Brazil
(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒ Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1).

Yes ☐ No ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7).

Yes ☐ No ☒

TIM S.A.

QUARTERLY INFORMATION

September 30, 2025

TIM S.A.

QUARTERLY INFORMATION

September 30, 2025

Contents

Notes are an integral part of the quarterly information.

Notes are an integral part of the quarterly information.

Notes are an integral part of the quarterly information.

Notes are an integral part of the quarterly information.

Notes are an integral part of the quarterly information.

Notes are an integral part of the quarterly information.

Notes are an integral part of the quarterly information.

Notes are an integral part of the quarterly information.

¹ Last twelve months IPCA ending September 2025; source: IBGE.

² The General and Administrative Expenses line had a non-recurring impact of R$19.0 million in 1Q25, related to costs with legal consulting services related to the settlement of the dispute with the former financial services partner.

³ The Other Operating Expenses (Revenues) line had a non-recurring impact of R$1.1 million in 2Q25, referring to contractual adjustments with legal advisors in the context of the end of the dispute with the former financial services partner.

⁴ EBITDA normalized according to the items outlined in the 'Costs' section.

⁵ Excludes the impact of fines from the decommissioning of the sites.

⁶ The Income Tax and Social Contribution line recorded non-recurring effects totaling -R$ 387 thousand in 2Q25 and -R$ 6.5 million in 1Q25.

⁷ Net Income normalized according to the items described in the section 'From EBITDA to Net Income’.

⁸ EBITDA-AL normalized according to the items described in the section 'From EBITDA to Net Income', excluding the impact of fines related to site decommissioning. For further details, refer to Annex 4 – EBITDA After Lease.

1.1. Corporate structure

TIM S.A. (“TIM” or “Company”) is a public limited company with Registered office in the city of Rio de Janeiro, RJ, and a subsidiary of TIM Brasil Serviços e Participações S.A. (“TIM Brasil”). TIM Brasil is a subsidiary of the Telecom Italia Group that holds 66.59% of the share capital of TIM S.A on September 30, 2025 (66.59% on December 31, 2024).

The TIM group (“Group”) comprises TIM and its associated company I-Systems.

The Company holds an authorization for Landline Switched Telephone Service (“STFC”) in Local, National Long-Distance and International Long-Distance modes, as well as Personal Mobile Service (“SMP”) and Multimedia Communication Service (“SCM”), in all Brazilian states and in the Federal District.

The Company’s shares are traded on B3 – Brasil, Bolsa, Balcão (“B3”). Additionally, TIM has American Depositary Receipts (ADRs), Level II, traded on the New York Stock Exchange (NYSE) – USA. As a result, the company is subject to the rules of the Brazilian Securities and Exchange Commission (“CVM”) and the Brazilian Securities and Exchange Commission (“SEC”). In order to comply with good market practices, the company adopts as a principle the simultaneous disclosure of its financial information in both markets, in reais, in Portuguese and English.

On September 30, 2025, TIM holds a 49% equity interest (49% on December 31, 2024) in the company I-Systems (associated company).

The quarterly information were prepared and are being presented according to the accounting practices adopted in Brazil, which comprise the CVM standards and pronouncements, guidance and interpretations issued by the Accounting Pronouncement Committee (“CPC”) and in compliance with the International Financial Reporting Standards (IFRS) issued by the International Accounting Standards Board (IASB), currently named “IFRS Accounting Standards” by the IFRS Foundation.

Additionally, the Company considered the guidelines provided for in Technical Guideline OCPC 07 - Evidencing upon Disclosure of General Purpose Financial-Accounting Reports in the preparation of its quarterly information. Accordingly, relevant information of the quarterly information is being evidenced and corresponds to the information used by management when administrating.

The material accounting policies applied in the preparation of this quarterly information are below and/or presented in its respective notes. Those policies were consistently applied in the periods presented.

a. General criteria for preparation and disclosure

The quarterly information was prepared considering the historical cost as value basis, except regarding the derivative financial instruments that were measured at fair value.

Assets and liabilities are classified according to their degree of liquidity and collectability. They are reported as current when they are likely to be realized or settled over the next 12 months. Otherwise, they are stated as non-current. The exception to this procedure involves deferred income tax and social contribution balances (assets and liabilities) and provision for lawsuits and administrative proceedings that are fully classified as non-current.

In connection with the preparation of this quarterly information, Management concluded that there is no evidence of uncertainties about the Company’s going concern. Therefore, the quarterly information was prepared based on the going concern assumption.

On September 30, 2025, the Company reported a net profit of R$ 2,980,714. The Company’s current liabilities exceeded total current assets by R$ 592,595. On September 30, 2025, the Company’s shareholders’ equity is positive by R$ 25,213,227.

The presentation of the Statement of Value Added is required by Brazilian corporate law and the accounting practices adopted in Brazil applicable to publicly-held companies. The DVA was prepared according to the criteria set forth in CPC Technical Pronouncement No. 09 - “Statement of Value Added”. The IFRS do not require the presentation of this statement. Consequently, according to IFRS, this statement is presented as supplementary information, without prejudice to the set of quarterly information.

Interests paid from loans and financing are classified as financing cash flow in the statement of cash flow as it represents costs of obtaining financial resources.

b. Functional and presentation currency

The currency of presentation of the quarterly information is the Real (R$), which is also the functional currency of the Company and its associated company.

Transactions in foreign currency are recognized by the exchange rate on the date of transaction. Monetary items in foreign currency are translated into Brazilian reais at the foreign exchange rate prevailing on the balance sheet date, informed by the Central Bank of Brazil. Foreign exchange gains and losses linked to these items are recorded in the statement of income.

Operating segments are components of the entity that carry out business activities from which revenues can be obtained and expenses incurred. Its operating results are regularly reviewed by the entity's main operations manager, who makes decisions on resource allocation and evaluates segment performance. For the segment to exist, individualized financial information is required.

The main operational decision maker in the Company, responsible for the allocation of resources and periodically evaluating performance, is the Executive Board, which, along with the Board of Directors, are responsible for making the strategic decisions of the company and its management.

The Group’s strategy is focused on optimizing results, and all the operating activities of the group are concentrated in TIM S.A. Although there are diverse activities, decision makers understand that the company represents only one business segment and do not contemplate specific strategies focused only on one service line. All decisions regarding strategic, financial planning, purchases, investments and investment of resources are made on a consolidated basis. The aim is to maximize the result obtained by operating the SMP, STFC and SCM licenses.

Business combinations are accounted for under the acquisition method. The cost of an acquisition is measured for the consideration amount transferred, which is valuated on fair value basis on the acquisition date, including the value of any non-controlling interest in the acquiree, regardless of their proportion. For each business combination the Company chooses to measure the non-controlling interest in the acquiree at the fair value or based on its proportional interest in the net assets identifiable of the acquiree. Costs directly attributable to the acquisition are accounted for as expense when incurred.

On acquiring a business, the Group assesses the financial assets and liabilities assumed in order to rate and to allocate them in accordance with contractual terms, economic circumstances and pertinent conditions on the acquisition date, which includes segregation by the acquired entity of built-in derivatives existing in the acquired entity’s host contracts.

Any contingent payments to be transferred by the acquiree will be recognized at fair value on the acquisition date. Subsequent changes to the fair value of the contingent consideration which is deemed to be a liability should be recognized in accordance with CPC 48 in the statement of income.

Initially, goodwill is initially measured as being the excess of consideration transferred in relation to net assets acquired (acquired identifiable assets and assumed liabilities) measured at fair value on acquisition date. If consideration is lower than fair value of net assets acquired, the difference must be recognized as gain in bargain purchase in the statement of income on the acquisition date.

After initial recognition, the goodwill is carried at cost less any accumulated impairment losses. For impairment testing purposes, goodwill acquired in a business combination is, from the acquisition date, allocated to each cash-generating units of the Group that are expected to benefit by the synergies of combination, regardless of other assets or liabilities of the acquiree being allocated to those units.

When the goodwill is part of a cash generating unit and a portion of this unit is disposed of, the goodwill associated with the disposed portion should be included in the cost of the operation when calculating gains or losses in the disposal. The goodwill disposed under these circumstances of this operation is determined based on the proportional values of the portion disposed of, in relation to the cash generating unit maintained.

This quarterly information was approved by the Company's Board of Directors on November 3, 2025.

g.1 The following new standards/amendments were issued by the Accounting Pronouncement Committee (“CPC”) and International Accounting Standards Board (IASB), are effective for the year ended September 30, 2025.

IAS 21/CPC 02 (R2) – Effects of changes in exchange rates and translation of financial statements

In March 2024, the IASB issued an amendment regarding Lack of Exchangeability, seeking to define the concept of convertible currency and provide guidance on procedures for non-convertible currencies, determining that convertibility should be assessed at the measurement date based on the purpose of the transaction. If the currency is not convertible, the entity must estimate the exchange rate that reflects market conditions. In situations with multiple rates, the one that best represents the settlement of the cash flows should be used.

The pronouncement also highlights the importance of disclosures about non-convertible currencies, so that users of the financial statements understand the financial impacts, risks involved and criteria used in estimating the exchange rate.

The amendments are effective for financial statement periods starting on or after January 1, 2025.

The Company assessed and did not identify any material impact on the Company’s quarterly information.

CPC 18 (R3) - Investment in associated company, subsidiary and joint venture

In September 2024, the Accounting Pronouncements Committee (CPC) amended Technical Pronouncement CPC 18 (R3) to align Brazilian accounting standards with the IASB’s international standards.

CPC 18 currently allows the equity method (MEP) in the measurement of investments in subsidiaries in the Separate Financial Statements, following changes in international standards. This convergence harmonizes the accounting practices adopted in Brazil with the international ones, without generating material impacts, only editorial and normative adjustments.

The amendments are effective for financial statement periods starting on or after January 1, 2025.

The Company assessed and did not identify any material impact on the Company’s quarterly information.

International Tax Reform - Pillar Two Model Rules - Amendments to IAS 12

The amendments to IAS 12 (equivalent to CPC 32 – Income Taxes) were introduced in response to the OECD Pillar Two rules on BEPS and include the following:

·     Disclosure requirements for affected entities to help users of financial statements better understand an entity’s exposure to Pillar Two income taxes arising from such legislation, especially before the effective date.

Pursuant to paragraphs 88C and 88D of CPC 32 - Income Taxes, the Company informs that it is assessing the possible impacts arising from the Pillar Two legislation, a global initiative of the Organization for Economic Cooperation and Development (“OECD”). This legislation establishes a minimum tax rate for large corporate groups that fall within the scope of said rules, which must calculate their effective tax rate in each country where they operate. In the context of this regulation, this rate is called the “GloBE Effective Tax Rate”.

If the GloBE Effective Tax Rate of any entity in the economic group, considered by jurisdiction in which the group operates, is lower than the minimum rate of 15%, the multinational will undertake to pay an additional tax on income, referring to the difference between its effective GloBE rate and the established minimum rate.

This rule was initially introduced by Provisional Act 1262 of October 3, 2024 and was subsequently subject to Law 15079 of December 27, 2024, which creates the Additional Social Contribution on Net Profit (CSLL) in the process of adapting Brazilian legislation to the Global Rules Against Base Erosion –- GloBE Rules as of 2025.

The aforementioned rules will apply to our group as of 2025, given that its constituent entities have earned revenues in excess of seven hundred and fifty million euros (€ 750,000,000.00) in the Consolidated Financial Statements of the Final Investing Entity in the last four (4) years. The Company is carrying out studies to verify possible impacts of the application of Pillar Two. So far, this rule has not had any effects on the Company’s collections, and the expectation is that it will not have significant impacts, as the Company meets the established limits.

g.2 The following new standards were issued by Comitê de Pronunciamentos Contábeis [Accounting pronouncements committee] (CPC) and the International Accounting Standards Board (IASB), but are not in effect for the period ended on September 30, 2025. The Company intends to adopt these new and amended standards and interpretations, if applicable, when they come into force.

IFRS 18: Presentation and disclosure of financial statements

In April 2024, the IASB issued IFRS 18, which replaces IAS 1 (equivalent to CPC 26 (R1) - Presentation of Financial Statements. IFRS 18 introduces new requirements for presentation within the statement of income, including specified totals and subtotals. Moreover+, entities are required to classify all revenues and expenses within the statement of income in one of five categories: operating, investment, financing, income taxes and discontinued operations, of which the first three are new.

The standard also requires the disclosure of performance measures defined by management, subtotals of revenues and expenses, and includes new requirements for the aggregation and disaggregation of financial information based on the identified “functions” of the primary financial statements (PFS) and notes.

Furthermore, restricted scope amendments were made to IAS 7 (equivalent to CPC 03 (R2) - Statement of Cash Flows), which include changing the starting point for determining cash flows from operations using the indirect method, from “income or loss for the period” to “operating income +r loss” and removing the option to classify cash flows from dividends and interest. In addition, there are consequent amendments in several other standards.

IFRS 18 and the amendments to the other standards will come into force for reporting periods beginning on or after January 01, 2027, with early adoption permitted, and must be disclosed, although in Brazil early adoption is not allowed. IFRS 18 will be applied retrospectively.

The Company is currently working to identify all the impacts that the changes will have on the primary financial statements and notes to the financial statements.

Amendment to IFRS 9 – Disclosure of quantitative information for contractual terms

In May 2024, the IASB issued amendments to IFRS 9 related to financial assets, establishing that entities must disclose quantitative information, such as a range of possible changes in contractual cash flows. This means that entities need to provide both qualitative and quantitative information about the contractual terms that may impact the value of said cash flows. For example, possible changes in contractual interest rates arising from contingent events associated with ESG (environmental, social and governance) targets must be disclosed.

The amendments are effective for financial statement periods starting on or after January 1, 2026.

The Company is assessing the impacts to ensure that all information complies with the standard.

Accounting estimates and judgments are continuously assessed based on the Company's historical experience and on other factors, such as expectations of future events, considering the circumstances present on the base date of quarterly information.

By definition, resulting accounting estimates are seldom equal to the respective actual income (loss). The estimates and assumptions that present a significant risk, with the probability of causing a material adjustment to the book values of assets and liabilities for the fiscal period, are covered below.

(a)       Provision for legal and tax administrative proceedings

The legal and tax administrative proceedings are analyzed by the Management along with its legal advisors (internal and external). The Company considers factors in its analysis such as hierarchy of laws, precedents available, recent court judgments, their relevance in the legal system and payment history. These assessments involve Management’s judgment (note 24).

(b)       Fair value of derivatives and other financial instruments

The financial instruments presented in the balance sheet at fair value are measured using valuation techniques that consider observable data or observable data derived from market (note 37).

(c)       Unbilled revenues

Since some cut dates for billing occur at intermediate dates within the months of the year, as the end of each month there are revenues earned by the Company, but not actually invoiced to its customers. These unbilled revenues are recorded based on estimate that takes into consideration historical consumption data, number of days elapsed since the last billing date, among others (note 28).

(d)       Leases

The Company has a significant number of the lease contracts in which it acts a lessee (Note 18), and with the adoption of the accounting standard IFRS 16 / CPC 06 (R2) – Leases, on January 1, 2019, certain judgments were exercised by Company’s management in measuring lease liabilities and right-of-use assets, such as: (i) estimate of the lease term, considering non-cancellable period and the period covered by options to extend the contract term, when the exercise depends only from the Company, and this exercise is reasonably certain; and (ii) using certain assumptions to calculate the discount rate.

The company is not able to readily determine the interest rate implicit on the lease and, therefore, considers its incremental rate on loans to measure lease liabilities. Incremental rate on the lessee’s loan is the interest rate that the lessee would have to pay when borrowing, for a similar term and with a similar guarantee, the resources necessary to obtain the asset with a value similar to the right of use asset in a similar economic environment. The Company estimates the incremental rate using observable data (such as market interest rates) when available and considers aspects that are specific to the Company (such as the cost of debt) in this estimate.

Cash and cash equivalents are financial assets measured at amortized cost or at fair value through profit or loss, respectively.

Company’s Management classifies its financial assets upon initial recognition.

Bank certificates of deposit (“CDBs”) are nominative securities issued by banks and sold to the public as a form of fund raising. These securities can be traded during the contracted term, at any time, which gives them high liquidity, their adjustment is linked to the percentage of the Interbank Deposit Certificate (CDI), there is no risk of significant impairment in their value and they are used to fulfill the Company’s short-term obligations.

The average remuneration of CDB investments in the nine-month period ended September 30, 2025 is 100.43% p.a. (101.09% on December 31, 2024) of the variation of the Interbank Deposit Certificate - CDI.

Comprise financial assets measured at fair value through profit or loss.

(i) Since 2017, the Company, with the aim of using tax deductibility benefit for income tax purposes, started investing in the National Film Industry Financing Fund (FUNCINE). The average remuneration for the nine-month period ended September 30, 2025, was 0.18% p.a. (1.47% p.a. on December 31, 2024).

(ii) Fundo Soberano is composed only of federal government bonds. The average remuneration of FICs in the nine-month period ended September 30, 2025 was 99.33% p.a. of the variation of the Interbank Deposit Certificate - CDI (99.20% p.a. on December 31, 2024).

(iii) The Company invests in open FIC's (Quota Investment Fund). Funds are mostly made up of federal government bonds and papers from financial institutions, mostly AAA (highest quality). The average remuneration of FICs in the nine-month period of 2025 was 102.38% p.a. of the variation of the Interbank Deposit Certificate - CDI (105.14% p.a. on December 31, 2024).

(a) Government bonds are fixed income financial instruments issued by the National Treasury to finance the activities of the Federal Government.

(b) CDB operations are securities issued by banks with the commitment of buyback by the bank itself, having their correction linked to the percentage of the Interbank Deposit Certificate (CDI).

(c) The Financial bills is a fix income tittle emitted by financial institutions.

(d) Is represented by: Debentures, FIDC, commercial notes, promissory notes, bank credit note.

These are financial assets measured at amortized cost, and refer to accounts receivable from users of telecommunications services, from network use (interconnection) and from sales of handsets and accessories. Accounts receivable are recorded at the price charged at the time of the transaction. The balances of accounts receivable also include services provided and not billed (“unbilled”) up to the balance sheet date. Trade accounts receivable are initially recognized at fair value and, subsequently, measured at amortized cost using the effective interest rate method less provision for expected credit losses (“impairment”).

The provision for expected credit losses was recognized as a decrease in accounts receivable based on the profile of the subscriber portfolio, the aging of overdue accounts receivable, the economic situation, the risks involved in each case and the collection curve, at an amount deemed sufficient by Management, as adjusted to reflect current and prospective information on macroeconomic factors that affect the customers’ ability to settle the receivables.

The fair value of trade accounts receivable equals the book value recorded as at September 30, 2025 and December 31, 2024.

Amounts expected to be received in more than 12 months are classified as long-term.

The average rate considered in calculating the present value of accounts receivable recorded in the long term is 0.58% p.m. (0.58% p.m. on December 31, 2024).

(i) Amounts to be received arising from the agreement made between TIM and Banco C6 on February 11, 2025 after the approval of CIMA (Cayman Islands Monetary Authority) in March 2025, for the sale of all shares (Note 12) and outstanding subscription warrant held by TIM (Note 37) of the Company at C6 Bank, for a total amount of R$ 520 million. By September 30, 2025, approximately 10% of the amount was received. The remaining balance, of R$ 468 million, will be settled during the year.

The movement of the provision for expected credit losses, accounted for as an asset reduction account, was as follows:

The aging of accounts receivable is as follows:

Inventories are presented at the average acquisition cost. A loss is recognized to adjust the cost of Handsets and accessories to the net realizable value (selling price) when this value is less than the average acquisition cost.

In 2021, based on a decision from the Federal Supreme Court (STF) regarding the non-levy of IRPJ and CSLL on the correction of SELIC in cases of undue enrichment, TIM recorded recoverable IRPJ and CSLL based on its best estimate at that time, amounting to R$ 535 million (principal). Until September 30, 2025, the total monetary restatement recognized was R$ 132 million.

In the third quarter of 2023, TIM’s lawsuit received a favorable final and unappealable decision and the Company obtained credit approval from the Brazilian Federal Revenue Service. As a result, it carried out the reclassification of R$ 156 million for deferred income tax and social contribution, with R$ 114 million and R$ 42 million related to tax loss and negative CSLL basis, respectively.

In the years 2023 and 2024, the Company used R$ 151 million and R$ 231 million, respectively, in credits to offset federal taxes. In 2025, R$ 105 million of these credits was offset.

Current income tax and social contribution charges are calculated on the basis of the tax laws enacted, or substantially enacted, up to the balance sheet date.

The legislation allows companies to opt for quarterly or monthly payment of income tax and social contribution. In 2025, the Company has chosen to make the quarterly payment of income tax and social contribution.

8.c Deferred income tax and social contribution

Deferred income tax and social contribution are recognized on (1) tax losses and accumulated tax loss carryforwards, when applicable; and (2) temporary differences arising from differences between the tax basis of assets and liabilities and their book values in the quarterly information. Deferred income tax is determined using the tax rates (and tax laws) enacted, or substantially enacted, up to the balance sheet date. Subsequent changes in tax rates or tax legislation may modify the deferred tax credit and debit balances.

Deferred tax assets on income tax and social contribution are recognized only according to the profitable track record and/or when based on the annual forecasts prepared by the Company.

The balances of deferred income tax assets and liabilities are presented at net value in balance sheet when there is the legal right and the intention of offsetting them upon calculation of current taxes, in general related to the same legal entity and the same tax authority. Accordingly, deferred tax assets and liabilities in different entities are in general presented separately, and not at net balance.

On September 30, 2025 and December 31, 2024, the prevailing tax rates were 25% for income tax and 9% for social contribution. In addition, there is no statute of limitation in regard to the income tax and social contribution carried forward losses, which it can be offset by up to 30% of the taxable profit reached at each fiscal year, according to the current tax legislation.

The amounts recorded are as follows:

(i) Mainly represented by the Fistel fee (TFF) for the financial years 2020-2025 of TIM S.A. and the TFF referring to Cozani's 2022 financial year. The Operating Inspection Fee (TFF) for the years 2020 and 2025 of TIM S.A. and TFF for 2022 of Cozani had its payments suspended by virtue of an injunction and, therefore, still do not have a specific date for payment. See Note 22 for details.

(ii) Represents the addition of new lease contracts. The temporary difference of the IFRS 16 contracts is due to the difference in the timing of recognition of the accounting (interest and depreciation) and tax expense (provision of service), under the terms of the current legislation.

(iii) As of the 1Q20, TIM S.A. excludes the portion of acceleration of depreciation of movable assets belonging to property, plant and equipment from the calculation basis of the IRPJ and CSLL, due to their uninterrupted use in three operating shifts, supported by technical expert report, as provided for in Article 323 of the RIR/2018, or by the adequacy to the tax depreciation provided for in IN 1700/2017.

(iv) Refers to deferred charges on the adjustment at fair value of the non-controlling interest calculated in the sale of Fiber Co (currently I-Systems), which took place in November 2021, from TIM S.A. to IHS Fiber Brasil - Cessão de Infraestruturas Ltda (see Note 14).

(v) Represents the deferred charges recorded, referring to the impairment of tangible assets recognized by Cozani before its acquisition in April 2022, which has been amortized over the estimated useful life of the asset.

The Company based on a history of profitability and based on projections of future taxable results, constitutes deferred income tax credits and social contribution on all of its temporary differences.

The Company used deferred credits arising from tax losses and negative social contribution bases in the amount of R$ 12 million in the period from January to September 2025 (R$ 189 million as of December 31, 2024).

8.d Expense with current and deferred income tax and social contribution

The reconciliation between income tax and social contribution expense as calculated by applying combined tax rates and amounts reflected in income (loss) is as follows:

(i) The amounts of recoverable ICMS (state VAT) are mainly comprised by:

(a) credits on the acquisition of property, plant and equipment directly related to the provision of telecommunication services (credits divided over 48 months).

(b) ICMS amounts paid under the tax substitution regime from goods acquired for resale, mainly mobile handsets, chips, tablets and modems sold by TIM.

(ii) The current balance is mostly composed of credits arising from the non-cumulative taxation regime.

(i) The Fistel rate is appropriated monthly to the income (loss).

(ii) Represent prepaid payments of advertising expenses for products and services of the TIM brand that are recognized in the result according to the period of serving the advertisement.

(iii) It is substantially represented by incremental costs related to sales commissions paid to partners for obtaining customer contracts arising from the adoption of IFRS 15/ CPC 47, which are deferred to the result in accordance with the term of the contract and/or economic benefit, usually from 1 to 2 years.

(iv) Represent the costs of installing a neutral network deferred over the term of the contract.

They are recorded at historical cost and updated according to current legislation.

(i) Refer to legal blockages directly in the company's current accounts and interest earning bank deposits linked to certain legal proceedings. This amount is periodically analyzed and when identified, reclassification is made to one of the other specific accounts of the legal deposit item.

Civil

These are court deposits to guarantee the execution of civil proceedings where the Company is challenging the amounts involved. Most of these proceedings refer to lawsuits filed by customers, involving issues of consumer rights, among others.

There are some processes with differentiated matters, for instance, in which the value set by ANATEL for vacating certain transmission sub-bands is discussed, enabling the implementation of 4G technology. In this case, the amount under discussion updated deposited in court is R$ 92,647 (R$ 88,147 on December 31, 2024).

Labor

These are amounts deposited in court as guarantees for the execution and the filing of appropriate appeals, where the relevant matters or amounts involved are still being discussed. The total amount has been allocated between the various claims filed by registered employees and third-party service providers.

Tax

The Company has legal deposits in the total, restated and estimated amount of R$ 260,249 (R$ 239,093 on December 31, 2024), relating to tax matters, made to support several ongoing legal discussions. Such deposits mainly relate to the following discussions:

They are recognized at fair value on the date of acquisition or issue. Such financial assets are subsequently measured at fair value through profit or loss. Changes arising from the fair value measurement, where applicable, shall be recognized in the result when incurred, under the line of financial income.

(i) In March 2025, the approval of the Cayman Islands was obtained from Monetary Authority (CIMA) for the Agreement signed on February 11, 2025, between the Company and Banco C6 was signed. Its purpose was to terminate the partnership between the parties and extinguish all ongoing disputes, including four arbitration proceedings. The Agreement includes the full transfer of the Company’s interest, including all shares and outstanding subscription warrants held by TIM. With the formalization of the Agreement, in the first quarter of 2025, the subscription warrant was fully written off.

(ii) The Company has invested approximately R$ 320 million on September 30, 2025 (R$ 212 million in 2024) in the Investment fund focused on 5G solutions “Upload Ventures Growth” (“5G Fund”), reinforcing its commitment to boosting the development of solutions based on 5G technology.

Out of this total amount, on January 16, 2025, the Company made contributions in dollars of approximately R$ 85 million (R$ 185 million until 2024) to the 5G Fund.

According to the requirements of IFRS 9 / CPC 48, the financial instrument must be valued at its fair value and the Company must disclose the level classification of each financial instrument. See Note 37 in the section on Financial instruments measured at fair value for details of this information.

(iii) In April 2022, the Company entered into a partnership with EXA Serviços de Tecnologia (“EXA”) to provide digital services and entertainment to TIM’s customer base. Said partnership also provided for commission payments by EXA to TIM as a result of TIM’s customers that acquire services from this partnership, as well as TIM’s right to subscribe to shares upon payment of a consideration.

At the end of 2024, the contract with the new partnership terms was completed and TIM acquired the right to subscribe for 27% of EXA’s shares for a consideration of R$ 174 million. The value of the financial asset was recorded at fair value for R$ 175 million and accounts for 27% of the fair value of TIM’s right to participate in EXA. This right must be exercised within the next 24 months, after the exercise conditions and corporate approval have been met.

The ownership interest in associated company is valued using the equity accounting method.

I-Systems

In November 2021, as a result of the spin-off of net assets from the broadband business and creation of I-Systems, TIM S.A. disposed of 51% of its equity interest on behalf of IHS. As a result of this transaction, a loss of control took place and TIM S.A. no longer consolidates the Company, recording the investment in the associated company in the amount of R$ 1,612,957, at fair value, for the remaining minority interest (non-controlling) of 49%.

TIM S.A. has 49% (49% on December 31, 2024) in the share capital of I-Systems. The following table represents summarized financial information about the investments of I-Systems:

Property, plant and equipment are measured at acquisition and/or construction cost, less accumulated depreciation and impairment losses (the latter only if applicable). Depreciation is calculated based on the straight-line method over terms that consider the expected useful lives of the assets and their residual values. On September 30, 2025 and December 31, 2024, the Company has no indication of impairment in its property, plant and equipment.

The estimated costs of dismantling towers and equipment on rented properties are capitalized and depreciated over the estimated useful lives of these assets. The Company recognizes the present value of these costs in property, plant and equipment with a counter-entry to the liability “provision for future asset retirement”. The interest incurred in updating the provision is classified as financial expenses.

Gains and losses on disposal are determined by comparing the amounts of these disposals with the book value at the time of the transaction and are recognized in “other operating expenses (revenues), net” in the statement of income.

The construction in progress represents the cost of projects in progress related to the construction of networks and/or other tangible assets in the period of their construction and installation, until the moment they come into operation, when they will be transferred to the corresponding accounts of these assets. Since the capitalization criteria set forth in IAS 23/CPC 20 were not met, the costs of loans are classified as financial expenses in the period in which they are incurred.

The lease rights of use are represented by leased agreements of identifiable assets within the scope of IFRS 16/CPC 06 (R2) standard. These rights refer to leases of network infrastructure, stores and kiosks, real estate, land (Network) and fiber, as below: