AT&T美股招股说明书(2026-07-29版)

Prospectus SupplementJuly27, 2026(To Prospectus dated February28, 2025) AT&T INC. €1,000,000,000 3.600% Global Notes due 2030€1,250,000,000 4.150% Global Notes due 2034€1,000,000,000 4.550% Global Notes due 2038€850,000,000 5.050% Global Notes due 2045£550,000,000 7.050% Global Notes due 2052 We will pay interest on the 3.600% Global Notes due 2030 (the “2030 Notes”) on August3 of each year, commencing on August3, 2027, the 4.150% GlobalNotes due 2034 (the “2034 Notes”) on August3 of each year, commencing on August3, 2027, the 4.550% Global Notes due 2038 (the “2038 Notes”) on August3 ofeach year, commencing on August3, 2027 and the 5.050% Global Notes due 2045 (the “2045 Notes”) on August3 of each year, commencing on August3, 2027 and onthe 7.050% Global Notes due 2052 (the “2052 Notes”) on February3 and August3 of each year, commencing on February3, 2027. The 2030 Notes will mature onAugust3, 2030, the 2034 Notes will mature on August3, 2034, the 2038 Notes will mature on August3, 2038, the 2045 Notes will mature on August3, 2045 and the2052 Notes will mature on August3, 2052. The 2030 Notes, the 2034 Notes, the 2038 Notes, the 2045 Notes and the 2052 Notes are collectively referred to as the“Notes”. We may redeem some or all of each series of the Notes at any time and from time to time at the prices and at the times indicated for each series under the heading“Description of the Notes—Optional Redemption of the Notes” beginning on pageS-7 of this prospectus supplement. The 2030 Notes, the 2034 Notes, the 2038 Notesand the 2045 Notes will be issued in minimum denominations of €100,000 and integral multiples of €1,000 in excess thereof, and the 2052 Notes will be issued inminimum denominations of £100,000 and integral multiples of £1,000 in excess thereof. The Notes are new issues of securities with no established trading market. We intend to apply to list the Notes on the New York Stock Exchange. We expecttrading in the Notes on the New York Stock Exchange to begin within 30 days after the original issue date. Currently, there is no public market for the Notes. See “Risk Factors” beginning on page 7 of our Annual Report on Form 10-K for the fiscal year ended December31, 2025, whichis incorporated by reference herein, to read about factors you should consider before investing in the Notes. Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed upon theaccuracy or adequacy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. Table of Contents The underwriters expect to deliver the Notes in book-entry form only through the facilities of Clearstream Banking S.A. and Euroclear BankSA/NV against payment on or about August3, 2026. BarclaysBBVABofASecurities CitigroupSantander We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you withdifferent or inconsistent information, we take no responsibility for, nor can we provide any assurance as to the reliability of, any other information that othersmay give you. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. Youshould assume that the information appearing in this prospectus supplement and the accompanying prospectus, as well as information we previously filed withthe Securities and Exchange Commission and incorporated by reference, is accurate as of their respective dates. Our business, financial condition, results ofoperations and prospects may have changed since those dates. The Notes are offered globally for sale in those jurisdictions in the United States, Canada, Europe, Asia and elsewhere where it is lawful to make such References herein to “$” and “dollars” are to the lawful currency of the United States. References to “€” and “euro” are to the lawful currency of themember states of the European Monetary Union that have adopted or that adopt the single currency in accordance with the treaty establishing the EuropeanCommunity, as amended by the Treaty on European Union. References herein to “£” and “GBP” are to the lawful currency of the United Kingdom. Thefinancial information presented in this prospectus supplement has been prepared in accordance with generally accepted accounting principles in the UnitedStates. In connection with the issue of the Notes, Citigroup Global Markets Limited,as Stabilizing Manager (or persons acting on its behalf), may over-allot the Notes oreffect transactions with a view to supporting the market price of the Notes at a level higher than that which might otherwise prevail. However, there is no assurance thatthe Stabilizing Manager (or persons acting on its behalf) will undertake stabilization action. Any stabilization action may begin on or after the date on which adequatepublic disclosure of th