SEC Form FWP filed by LyondellBasell Industries NV

Issuer Free Writing Prospectus, dated November 10, 2025

Filed Pursuant to Rule 433 under the Securities Act of 1933

Registration No. 333-283755

LYB International Finance III, LLC

$500,000,000 5.125% Guaranteed Notes due 2031

$1,000,000,000 5.875% Guaranteed Notes due 2036

Pricing Term Sheet dated November 10, 2025

*A securities rating is not a recommendation to buy, sell or hold securities and may be revised or withdrawn at any time.

**Note: It is expected that delivery of the Notes will be made against payment therefor on or about November 13, 2025, which will be the second business day following the date of the pricing of the Notes (such settlement cycle being referred to as “T+2”). Under Rule 15c6-1 under the Securities Exchange Act of 1934, as amended, trades in the secondary market are generally required to settle in one business day, unless the parties to any such trade expressly agree otherwise. Accordingly, purchasers who wish to trade the Notes prior to the business day preceding the date of delivery of the Notes will be required, by virtue of the fact that the Notes will initially settle in T+2, to specify an alternate settlement arrangement at the time of any such trade to prevent a failed settlement. Purchasers of the Notes who wish to trade the Notes prior to the business day preceding the date of delivery of the Notes should consult their own advisors.

The issuer has filed a registration statement (including a prospectus) and a preliminary prospectus supplement with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement, the preliminary prospectus supplement and other documents the issuer has filed with the SEC that are incorporated into the prospectus supplement for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus and the related prospectus supplement if you request it by calling Citigroup Global Markets Inc. at 1-800-831-9146, Deutsche Bank Securities Inc. at 1-800-503-4611 or J.P. Morgan Securities LLC at 1-212-834-4533.

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