We may, at our option, redeem each series of the notes, in whole or in part, at any time and from time to time at the applicable redemption price described in thisprospectus supplement in “Description of the Notes—Optional Redemption.” We may also redeem each series of the notes at our option, in whole but not in part, at theapplicable redemption price described in this prospectus supplement if certain tax events occur as described in “Description of the Notes—Optional Tax Redemption.”We must offer to repurchase the notes upon the occurrence of a change of control triggering event at the price described in this prospectus supplement in “Descriptionof the Notes—Purchase of Notes upon a Change of Control Triggering Event.” We intend to use the net proceeds from this offering, together with proceeds from the sale of commercial paper and cash from operations, to purchase any andall of our $750.0million aggregate principal amount of 5.150% senior notes due 2027 and any and all of our $2.0billion aggregate principal amount of 4.400% seniornotes due 2049, including any premium and accrued and unpaid interest on the tendered notes, pursuant to the tender offer described above under “Summary—RecentDevelopments.” The offering and sale of each series of notes is not conditioned on the sale of any other series of notes. The notes will be our unsecured senior obligations and will rank equally with our other unsecured senior indebtedness from time to time outstanding. Each series of the notes is a new issue of securities with no established trading market. We currently intend to apply to list the notes on the NASDAQ GlobalMarket (“NASDAQ”). The listing application will be subject to approval by NASDAQ. If such listing is obtained, we have no obligation to maintain such listing forthe notes and we may delist the notes, or list the notes on one or more other national securities exchanges, at any time. We currently expect trading in the notes onNASDAQ to begin within 30 days after the original issue date. Investing in the notes involves risks. See “Risk Factors” beginning on page S-8 of this prospectus supplementand the risk factors incorporated by reference into this prospectus supplement and the accompanying prospectus. (1)Plus accrued interest if any, from, 2026, if settlement occurs after that date. We expect to deliver the notes to investors in registered book-entry only form through Euroclear Bank S.A./N.V., as operator of the Euroclear System(“Euroclear”) and Clearstream Banking S.A. (“Clearstream” and, together with Euroclear, the “ICSDs” and each, an “ICSD”), on or about, 2026. Uponissuance, the notes will be represented by one or more global notes in fully registered form (“global notes”), which are expected to be deposited with a commondepositary for Euroclear and Clearstream and registered in the name of a nominee of the common depositary. Table of Contents TABLE OF CONTENTS PROSPECTUSSUPPLEMENT ABOUT THIS PROSPECTUS SUPPLEMENTWHERE YOU CAN FIND MORE INFORMATIONFORWARD-LOOKING STATEMENTSSUMMARYRISK FACTORSISSUANCE IN EUROUSE OF PROCEEDSCAPITALIZATIONDESCRIPTION OF THE NOTESCERTAIN U.S. FEDERAL INCOME TAX CONSIDERATIONSUNDERWRITING (CONFLICTS OF INTEREST)VALIDITY OF THE NOTESEXPERTS PROSPECTUS ABOUT THIS PROSPECTUSFORWARD-LOOKING STATEMENTSRISK FACTORSFISERV, INC.FISERV FUNDING UNLIMITED COMPANYUSE OF PROCEEDSDESCRIPTION OF DEBT SECURITIES AND GUARANTEES OF DEBT SECURITIES DESCRIPTION OF CAPITAL STOCKDESCRIPTION OF DEPOSITARY SHARESDESCRIPTION OF WARRANTSDESCRIPTION OF PURCHASE CONTRACTSDESCRIPTION OF UNITSSELLING SHAREHOLDERSPLAN OF DISTRIBUTIONWHERE YOU CAN FIND MORE INFORMATIONLEGAL MATTERSEXPERTS Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This document has two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part isthe accompanying prospectus, which provides more general information, some of which may not apply to this offering. You should read the entireprospectus supplement, as well as the accompanying prospectus and the documents incorporated by reference that are described under “Where You CanFind More Information” in this prospectus supplement and the accompanying prospectus. In the event that the description of the offering in thisprospectus supplement is inconsistent with the accompanying prospectus, you should rely on the information contained in this prospectus supplement. We have not, and the underwriters have not, authorized any other person to provide you with different or additional information other than thatcontained or incorporated by reference in this prospectus supplement, the accompanying prospectus and any free writing prospectus that we haveauthorized for use in connection with this offering. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdictionwhere the offer or sale is not permitted. You should not assume that the information contained in or inco