美国运通美股招股说明书(2025-10-21版)

(To Prospectus Dated February9, 2024) $2,000,000,000American Express Company4.804%Fixed-to-FloatingRate Notes due October24, 2036 We are offering $2,000,000,000 principal amount of our 4.804%fixed-to-floatingrate notes due October24, 2036, or the notes. We will pay interest on the notes (i)from, and including, October24, 2025, to, but excluding, October24, 2035 at a rate per annum equal to 4.804%, payable semi-annually in arrearson April24 and October24 of each year, beginning April24, 2026 and ending on October24, 2035, and (ii)from, and including October24, 2035, to, but excluding, the maturity date at a rateper annum equal to Compounded SOFR (as defined in the accompanying prospectus) plus 1.237%, payable quarterly in arrears on January24, April24, July24 and October24, beginningJanuary24, 2036 and ending on the maturity date. The notes will mature on October24, 2036. We may redeem the notes (i)in whole or in part on or after April24, 2026 and prior to October24, 2035, (ii) in whole but not in part on October24, 2035 or (iii)in whole or in partduring the3-monthperiod prior to the maturity date, in each case at the applicable redemption price described under “Description of Notes” below. The notes will be our senior unsecuredobligations and will rank prior to all of our present and future subordinated indebtedness and on an equal basis with all of our other present and future senior unsecured indebtedness. We will not list the notes on any exchange. We will only issue the notes in book-entry form registered in the name of a nominee of The Depository Trust Company (“DTC”), NewYork, New York. Beneficial interests in thenotes will be shown on, and transfers of such interests will be made only through, records maintained by DTC and its participants, including Clearstream Banking, S.A. (“Clearstream”), andEuroclear Bank SA/ NV, as operator of the Euroclear system (“Euroclear”). Except as described in this prospectus supplement, we will not issue notes in definitive form. The underwriters are offering the notes for sale in those jurisdictions both inside and outside the United States where it is lawful to make such offers. Investing in the notes involves risks. You should carefully consider the information under “Risk Factors” beginning on page3of the accompanying prospectus and in ourAnnual Report on Form10-Kfor the year ended December31, 2024and our Quarterly Reports on Form10-Qfor the quarters endedMarch31, 2025,June 30, 2025andSeptember30, 2025which are incorporated herein by reference. The notes are not deposits or savings accounts. The notes are not insured or guaranteed by the Federal Deposit Insurance Corporation (“FDIC”) or by any othergovernmental agency or instrumentality. (1)Plus accrued interest, if any, from October24, 2025 to the date of delivery.(2)Before offering expenses.Delivery of the notes will be made on or about October24, 2025. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectussupplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense. SMBCNikko LloydsSecurities Table of Contents TABLE OF CONTENTS Prospectus Supplement About This Prospectus SupplementCautionary Statement Regarding Forward-Looking InformationUse Of ProceedsDescription of NotesCertain U.S. Federal Income Tax ConsequencesUnderwritingWhere You Can Find More InformationIncorporation of Certain Documents by ReferenceLegal MattersExperts Prospectus About This ProspectusWhere You Can Find More InformationIncorporation of Certain Documents by ReferenceForward-Looking Statements The CompanySummary of the Securities We May OfferRisk FactorsUse of Proceeds Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of the notes that we are offering andother matters relating to us and our financial condition. The second part is the accompanying prospectus, which gives more general information aboutsecurities we may offer from time to time, some of which does not apply to the notes that we are offering. The description of the terms of the notescontained in this prospectus supplement supplements the description under “Description of Debt Securities” in the accompanying prospectus, and to theextent it is inconsistent with that description, the information in this prospectus supplement replaces the information in the accompanying prospectus.Generally, when we refer to the prospectus, we are referring to both parts of this document combined. If information in this prospectus supplementdiffers from information in the accompanying prospectus, you should rely on the information in this prospectus supplement. When we use the terms “American Express,” the “Company,” “we,” “us” or “our” in this prospectus supplement, we mean American ExpressComp