DESCRIPTION OF THE NOTES

The following description of the general terms of the Notes should be read in conjunction with the statements under “Description of Debt Securities We May Offer” in the accompanying prospectus. If this summary differs in any way from the “Summary Description of the Securities We May Issue” in the accompanying prospectus, you should rely on this summary.

General

The Notes will be issued under our indenture, dated as of May 15, 2013, with The Bank of New York Mellon Trust Company, N.A., acting as trustee, as described under “Description of Debt Securities We May Offer” in the accompanying prospectus. The Notes will be our unsecured and unsubordinated obligations and will rank pari passu with all other indebtedness issued under our indenture. The Notes will constitute a single series under the indenture. Investors will have to pay for the Notes in euro. We will issue the Notes in fully registered form only and in minimum denominations of €100,000 and integral multiples of €1,000 in excess thereof.

We may issue definitive Notes in the limited circumstances set forth in “—The Clearing Systems—Certificated Notes” below. If we issue definitive Notes, principal of and interest on our Notes will be payable in the manner described below, the transfer of our Notes will be registrable, and our Notes will be exchangeable for Notes bearing identical terms and provisions, at the office of The Bank of New York Mellon, London Branch, the paying agent for our Notes pursuant to a paying agent agreement to be entered into in connection with the offering of the Notes, currently located at The Bank of New York Mellon, London Branch, 160 Queen Victoria Street, London EC4V 4AL. However, payment of interest, other than interest at maturity, or upon redemption, may be made by check mailed to the address of the person entitled to the interest as it appears on the security register at the close of business on the regular record date corresponding to the relevant interest payment date. Notwithstanding this, (1) the depositary, as holder of our Notes, or (2) a holder of more than €5 million in aggregate principal amount of Notes in definitive form can require the paying agent to make payments of interest, other than interest due at maturity, or upon redemption, by wire transfer of immediately available funds into an account maintained by the holder in the United States, by sending appropriate wire transfer instructions as long as the paying agent receives the instructions not less than ten days prior to the applicable interest payment date. Under the terms of the indenture, if the euro ceases to exist when payments on the Notes are due under any circumstances, AT&T may supplement the indenture to allow for payment in U.S. dollars. The principal and interest payable in U.S. dollars on a Note at maturity, or upon redemption, will be paid by wire transfer of immediately available funds against presentation of a Note at the office of the paying agent.

For purposes of the Notes, a business day means any day that is not a Saturday or Sunday and that, in the City of New York or the City of London, is not a day on which banking institutions are generally authorized or obligated by law to close, and is a day on which the Trans-European Automated Real-time Gross Settlement Express Transfer (TARGET) System, or any successor thereto, operates.

The Notes offered by this prospectus supplement will initially be limited to €2,250,000,000 aggregate principal amount and will mature on September 16, 2027. If the Maturity Date falls on a day that is not a EURIBOR business day, the payment of interest and principal will be made on the next succeeding EURIBOR business day, and no interest will accrue for the period from and after the Maturity Date.

The Notes offered by this prospectus supplement will bear interest from September 16, 2025 at a floating rate determined in the manner provided below, payable on March 16, June 16, September 16 and December 16 of each year (each such day, a “Floating Rate Interest Payment Date”), commencing on December 16, 2025, to the persons in whose names the Notes were registered at the close of business on the 15th day preceding the respective Floating Rate Interest Payment Date, subject to certain exceptions.

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The per annum interest rate on the Notes (the “Floating Interest Rate”) in effect for each day of a Floating Rate Interest Period (as defined below) will be equal to the Applicable EURIBOR Rate plus 40 basis points (0.400%). The Floating Interest Rate for each Floating Rate Interest Period will be set on March 16, June 16, September 16 and December 16 of each year, and will be set for the initial Floating Rate Interest Period on September 16, 2025 (each such date, a “Floating Rate Interest Reset Date”) until the principal on the Notes is paid or made available for payment (the “Floating Rate Principal Payment Date”). If any Floating Rate Interest Reset Date (other than the initial Floating Rate Interest Reset Date occurring on September 16, 2025) and Floating Rate Interest Payment Date would otherwise be a day that is not a EURIBOR business day, other than the interest payment date that is also the date of maturity, such Floating Rate Interest Reset Date and Floating Rate Interest Payment Date shall be the next succeeding EURIBOR business day, unless the next succeeding EURIBOR business day is in the next succeeding calendar month, in which case such Floating Rate Interest Reset Date and Floating Rate Interest Payment Date shall be the immediately preceding EURIBOR business day; and provided further, that if the date of maturity is not a EURIBOR business day, payment of principal and interest will be made on the next succeeding business day and no interest will accrue for the period from and after such date of maturity.

“EURIBOR business day” means any day that is not a Saturday or Sunday and that, in the City of New York or the City of London, is not a day on which banking institutions are generally authorized or obligated by law to close, and is a day on which the TARGET System, or any successor thereto, operates.

“Floating Rate Interest Period” shall mean the period from and including a Floating Rate Interest Reset Date to but excluding the next succeeding Floating Rate Interest Reset Date and, in the case of the last such period, from and including the Floating Rate Interest Reset Date immediately preceding the Maturity Date or Floating Rate Principal Payment Date, as the case may be, to but not including such Maturity Date or Floating Rate Principal Payment Date, as the case may be. If the Floating Rate Principal Payment Date or Maturity Date is not a EURIBOR business day, then the principal amount of the Notes plus accrued and unpaid interest thereon shall be paid on the next succeeding EURIBOR business day and no interest shall accrue for the Maturity Date, Floating Rate Principal Payment Date or any day thereafter.

The “Applicable EURIBOR Rate” shall mean the rate determined in accordance with the following provisions:

(1) Two prior TARGET days on which dealings in deposits in euros are transacted in the euro-zone interbank market preceding each Floating Rate Interest Reset Date (each such date, an “Interest Determination Date”), The Bank of New York Mellon Trust Company, N.A. (the “Calculation Agent”), as agent for AT&T, will determine the Applicable EURIBOR Rate which shall be the rate for deposits in euro having a maturity of three months commencing on the first day of the applicable interest period that appears on the Bloomberg Screen BBAM Page as of 11:00 a.m., Brussels time, on such Interest Determination Date. “Bloomberg Screen BBAM Page” means the display designated on page “BBAM” on Bloomberg (or such other page as may replace the “BBAM” page on that service or any successor service for the purpose of displaying euro-zone interbank offered rates for euro-denominated deposits of major banks). If the Applicable EURIBOR Rate on such Interest Determination Date does not appear on the Bloomberg Screen BBAM Page, the Applicable EURIBOR Rate will be determined as described in (2) below.

(2) With respect to an Interest Determination Date for which the Applicable EURIBOR Rate does not appear on the Bloomberg Screen BBAM Page as specified in (1) above, the Applicable EURIBOR Rate will be determined on the basis of the rates at which deposits in euro are offered by four major banks in the euro-zone interbank market selected by AT&T (the “Reference Banks”) at approximately 11:00 a.m., Brussels time, on such Interest Determination Date to prime banks in the euro-zone interbank market having a maturity of three months, and in a principal amount equal to an amount of not less than €1,000,000 that is representative for a single transaction in such market at such time. AT&T or its designee will request the principal euro-zone office of each of such Reference Banks to provide a quotation of its rate. If at least two such quotations are provided, the Applicable EURIBOR Rate on such Interest Determination Date will be the arithmetic mean (rounded upwards) of such quotations. If fewer than two quotations are provided, the

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Applicable EURIBOR Rate on such Interest Determination Date will be the arithmetic mean (rounded upwards) of the rates quoted by three major banks in the euro-zone selected by AT&T at approximately 11:00 a.m., Brussels time, on such Interest Determination Date for loans in euro to leading European banks, having a maturity of three months, and in a principal amount equal to an amount of not less than €1,000,000 that is representative for a single transaction in such market at such time; provided, however, that if the banks so selected as aforesaid by AT&T are not quoting as mentioned in this sentence, the relevant Floating Interest Rate for the Floating Rate Interest Period commencing on the Floating Rate Interest Reset Date following such Interest Determination Date will be the Floating Interest Rate in effect on such Interest Determination Date (i.e., the same as the rate determined for the immediately preceding Floating Rate Interest Reset Date).

The amount of interest for each day that the Notes are outstanding (the “Daily Interest Amount”) will be calculated by dividing the Floating Interest Rate in effect for such day by 360 and multiplying the result by the principal amount of the Notes (known as the “Actual/360” day count). The amount of interest to be paid on the Notes for any Floating Rate Interest Period will be calculated by adding the Daily Interest Amounts for each day in such Floating Rate Interest Period.

The Floating Interest Rate and amount of interest to be paid on the Notes for each Floating Rate Interest Period will be determined by the Calculation Agent. The Floating Interest Rate will in no event be lower than zero or higher than the maximum rate permitted by New York law as the same may be modified by United States law of general application. The Calculation Agent will, upon the request of any holder of the Notes, provide the interest rate then in effect with respect to the Notes. All calculations made by the Calculation Agent shall in the absence of manifest error be conclusive for all purposes and binding on AT&T and the holders of the Notes. So long as the Applicable EURIBOR Rate is required to be determined with respect to the Notes, there will at all times be a Calculation Agent. In the event that any then acting Calculation Agent shall be unable or unwilling to act, or that such Calculation Agent shall fail to duly establish the Applicable EURIBOR Rate for any Floating Rate Interest Period, or that AT&T proposes to remove such Calculation Agent, AT&T shall appoint itself or another person which is a bank, trust company, investment banking firm or other financial institution to act as the Calculation Agent.

None of the trustee, the paying agent or the calculation agent shall be under any obligation (i) to monitor, determine or verify the unavailability or cessation of EURIBOR (or any other benchmark), or whether or when there has occurred, or to give notice to any other transaction party of the occurrence of, any benchmark transition event or related benchmark replacement date, (ii) to select, determine or designate any benchmark replacement, or other successor or replacement benchmark index, or whether any conditions to the designation of such a rate or index have been satisfied, or (iii) to select, determine or designate any benchmark replacement adjustment, or other modifier to any replacement or successor index, or (iv) to determine whether or what benchmark replacement conforming changes are necessary or advisable, if any, in connection with any of the foregoing, including, but not limited to, adjustments as to any alternative spread thereon, the business day convention, interest determination dates or any other relevant methodology applicable to such substitute or successor benchmark. In connection with the foregoing, each of the trustee, paying agent and calculation agent shall be entitled to conclusively rely on any determinations made by us without independent investigation, and none will have any liability for actions taken at our direction in connection therewith.

None of the trustee, the paying agent or the calculation agent shall be liable for any inability, failure or delay on its part to perform any of its duties set forth in this prospectus supplement as a result of the unavailability of EURIBOR or other applicable benchmark replacement, including as a result of any failure, inability, delay, error or inaccuracy on the part of any other transaction party in providing any direction, instruction, notice or information required or contemplated by the terms of this prospectus supplement and reasonably required for the performance of such duties. None of the trustee, paying agent or calculation agent shall be responsible or liable for our actions or omissions, or for any failure or delay in the performance by us, nor shall any of the trustee, paying agent or calculation agent be under any obligation to oversee or monitor our performance.

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The Clearing Systems

Global Clearance and Settlement

The Notes will be issued in the form of one or more global notes (the “Global Notes”) in fully registered form, without coupons, and will be deposited on September 16, 2025 with a common depositary for, and in respect of interests held through, Euroclear Bank SA/NV, as operator of the Euroclear System (“Euroclear”), and Clearstream Banking S.A. (“Clearstream Luxembourg”). Except as described herein, certificates will not be issued in exchange for beneficial interests in the Global Notes.

Except as set forth below, the Global Notes may be transferred, in whole and not in part, only to Euroclear or Clearstream Luxembourg or their respective nominees.

Beneficial interests in the Global Notes will be represented, and transfers of such beneficial interests will be effected, through accounts of financial institutions acting on behalf of beneficial owners as direct or indirect participants in Euroclear or Clearstream Luxembourg. Those beneficial interests will be in denominations of €100,000 and integral multiples of €1,000 in excess thereof. Investors may hold Notes directly through Euroclear or Clearstream Luxembourg, if they are participants in such systems, or indirectly through organizations that are participants in such systems.

Owners of beneficial interests in the Global Notes will not be entitled to have Notes registered in their names, and will not receive or be entitled to receive physical delivery of Notes in definitive form. Except as provided below, beneficial owners will not be considered the owners or holders of the Notes under the indenture, including for purposes of receiving any reports delivered by us or the trustee pursuant to the indenture. Accordingly, each beneficial owner must rely on the procedures of the clearing systems and, if such person is not a participant of the clearing systems, on the procedures of the participant through which such person owns its interest, to exercise any rights of a holder under the indenture. Under existing industry practices, if we request any action of holders or a beneficial owner desires to give or take any action which a holder is entitled to give or take under the indenture, the clearing systems would authorize their participants holding the relevant beneficial interests to give or take action and the participants would authorize beneficial owners owning through the participants to give or take such action or would otherwise act upon the instructions of beneficial owners. Conveyance of notices and other communications by the clearing systems to their participants, by the participants to indirect participants and by the participants and indirect participants to beneficial owners will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time. The laws of some jurisdictions require that certain purchasers of securities take physical delivery of such securities in certificated form. These limits and laws may impair the ability to transfer beneficial interests in Global Notes.

Persons who are not Euroclear or Clearstream Luxembourg participants may beneficially own Notes held by the common depositary for Euroclear and Clearstream Luxembourg only through direct or indirect participants in Euroclear and Clearstream Luxembourg. So long as the common depositary for Euroclear and Clearstream Luxembourg is the registered owner of the Global Note, the common depositary for all purposes will be considered the sole holder of the Notes represented by the Global Note under the indenture and the Global Notes.

Certificated Notes

If the applicable depositary is at any time unwilling or unable to continue as depositary for the Global Notes and a successor depositary is not appointed by us within 90 days, we will issue the Notes in definitive form in exchange for the Global Notes. We will also issue the Notes in definitive form in exchange for the Global Notes if an event of default has occurred with regard to the Notes represented by the Global Notes and has not been cured or waived. In addition, we may at any time and in our sole discretion determine not to have the Notes represented by the Global Notes and, in that event, will issue the Notes in definitive form in exchange for the Global Notes. In any such instance, an owner of a beneficial interest in the Global Notes will be entitled to

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physical delivery in definitive form of the Notes represented by the Global Notes equal in principal amount to such beneficial interest and to have such Notes registered in its name. The Notes so issued in definitive form will be issued as registered in minimum denominations of €100,000 and integral multiples of €1,000 in excess thereof, unless otherwise specified by us. Our definitive form of the Notes can be transferred by presentation for registration to the registrar at its New York office and must be duly endorsed by the holder or his attorney duly authorized in writing, or accompanied by a written instrument or instruments of transfer in form satisfactory to us or the trustee duly executed by the holder or his attorney duly authorized in writing. We may require payment of a sum sufficient to cover any tax or other governmental charge that may be imposed in connection with any exchange or registration of transfer of definitive notes.

Clearing Systems

Euroclear. Euroclear has advised that it was created in 1968 to hold securities for its participants and to clear and settle transactions between Euroclear participants through simultaneous electronic book-entry delivery against payment, eliminating the need for physical movement of certificates and eliminating any risk from lack of simultaneous transfers of securities and cash. Euroclear provides various other services, including securities lending and borrowing and interfaces with domestic markets in several countries. Euroclear is owned by Euroclear Clearance System Public Limited Company (ECSplc) and operated through a license agreement by Euroclear Bank SA/NV, a bank incorporated under the laws of the Kingdom of Belgium as the “Euroclear operator.”

The Euroclear operator holds securities and book-entry interests in securities for participating organizations and facilitates the clearance and settlement of securities transactions between Euroclear participants, and between Euroclear participants and participants of certain other securities intermediaries through electronic book-entry changes in accounts of such participants or other securities intermediaries.

The Euroclear operator provides Euroclear participants, among other things, with safekeeping, administration, clearance and settlement, securities lending and borrowing, and related services.

Non-participants of Euroclear may hold and transfer book-entry interests in the securities through accounts with a direct participant of Euroclear or any other securities intermediary that holds a book-entry interest in the securities through one or more securities intermediaries standing between such other securities intermediary and the Euroclear operator.

The Euroclear operator is regulated and examined by the Belgian Banking and Finance Commission and the National Bank of Belgium.

Securities clearance accounts and cash accounts with the Euroclear operator are governed by the “Terms and Conditions Governing Use of Euroclear” and the related operating procedures of Euroclear, and applicable Belgian law, which are collectively referred to as the “terms and conditions.” The terms and conditions govern transfers of notes and cash within Euroclear, withdrawals of notes and cash from Euroclear, and receipts of payments with respect to notes in Euroclear. All notes in Euroclear are held on a fungible basis without attribution of specific certificates to specific securities clearance accounts. The Euroclear operator acts under the terms and conditions only on behalf of Euroclear participants, and has no record of or relationship with persons holding through Euroclear participants.

Distributions with respect to the Notes held beneficially through Euroclear will be credited to the cash accounts of Euroclear participants in accordance with the terms and conditions, to the extent received by the U.S. depositary for Euroclear.

Clearstream Luxembourg. Clearstream Luxembourg advises that it is incorporated under the laws of Luxembourg as a professional depositary. Clearstream Luxembourg holds securities for its participating

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organizations and facilitates the clearance and settlement of securities transactions between Clearstream Luxembourg participants through electronic book-entry changes in accounts of Clearstream Luxembourg participants, thereby eliminating the need for physical movement of certificates. Clearstream Luxembourg provides to Clearstream Luxembourg participants, among other things, services for safekeeping, administration, clearance and settlement of internationally traded securities and securities lending and borrowing. Clearstream Luxembourg interfaces with domestic markets in several countries. As a professional depositary, Clearstream Luxembourg is subject to regulation by the Luxembourg Monetary Institute. Clearstream Luxembourg participants are recognized financial institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations and may include the underwriters. Indirect access to Clearstream Luxembourg is also available to others, such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a Clearstream Luxembourg participant either directly or indirectly.

Distributions with respect to the Notes held beneficially through Clearstream Luxembourg will be credited to cash accounts of Clearstream Luxembourg participants in accordance with its rules and procedures, to the extent received by the U.S. depositary for Clearstream Luxembourg.

Euroclear and Clearstream Luxembourg Arrangements

So long as Euroclear or Clearstream Luxembourg or their nominee or their common depositary is the registered holder of the Global Notes, Euroclear, Clearstream Luxembourg or such nominee or common depositary, as the case may be, will be considered the sole owner or holder of the Notes represented by such Global Notes for all purposes under the indenture and the Notes. Payments of principal, interest and additional amounts, if any, in respect of the Global Notes will be made to Euroclear, Clearstream Luxembourg or such nominee or common depositary, as the case may be, as registered holder thereof. None of us, the trustee, any underwriter and any affiliate of any of the above or any person by whom any of the above is controlled (as such term is defined in the Securities Act of 1933) will have any responsibility or liability for any records relating to or payments made on account of beneficial ownership interests in the Global Notes or for maintaining, supervising or reviewing any records relating to such beneficial ownership interests.

Distributions of principal and interest with respect to the Global Notes will be credited in euro to the extent received by Euroclear or Clearstream Luxembourg from the trustee to the cash accounts of Euroclear or Clearstream Luxembourg customers in accordance with the relevant system’s rules and procedures.

Because Euroclear and Clearstream Luxembourg can only act on behalf of participants, who in turn act on behalf of indirect participants, the ability of a person having an interest in the Global Notes to pledge such interest to persons or entities which do not participate in the relevant clearing system, or otherwise take actions in respect of such interest, may be affected by the lack of a physical certificate in respect of such interest.

The holdings of book-entry interests in the Global Notes through Euroclear and Clearstream Luxembourg will be reflected in the book-entry accounts of each such institution. As necessary, the paying agent will adjust the amounts of the Global Notes on the register for the accounts of the common depositary to reflect the amounts of Notes held through Euroclear and Clearstream Luxembourg, respectively.

Initial Settlement

Investors holding their Notes through Euroclear or Clearstream Luxembourg accounts will follow the settlement procedures applicable to conventional eurobonds in registered form. Notes will be credited to the securities custody accounts of Euroclear and Clearstream Luxembourg holders on the settlement date against payment for value on the settlement date.

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Secondary Market Trading

Because the purchaser determines the place of delivery, it is important to establish at the time of trading of any Notes where both the purchaser’s and seller’s accounts are located to ensure that settlement can be made on the desired value date.

Secondary market sales of book-entry interests in the Notes held through Euroclear or Clearstream Luxembourg to purchasers of book-entry interests in the Global Note through Euroclear or Clearstream Luxembourg will be conducted in accordance with the normal rules and operating procedures of Euroclear and Clearstream Luxembourg and will be settled using the procedures applicable to conventional eurobonds in same-day funds.

You should be aware that investors will only be able to make and receive deliveries, payments and other communications involving the Notes through Euroclear and Clearstream Luxembourg on days when those systems are open for business. Those systems may not be open for business on days when banks, brokers and other institutions are open for business in the United States.

In addition, because of time-zone differences, there may be problems with completing transactions involving Euroclear and Clearstream Luxembourg on the same business day as in the United States. U.S. investors who wish to transfer their interests in the Notes, or to make or receive a payment or delivery of the Notes, on a particular day, may find that the transactions will not be performed until the next business day in Luxembourg or Brussels, depending on whether Euroclear or Clearstream Luxembourg is used.

Euroclear and Clearstream Luxembourg will credit payments to the cash accounts of Euroclear participants or Clearstream Luxembourg customers in accordance with the relevant system’s rules and procedures, to the extent received by its depositary. Clearstream Luxembourg or the Euroclear operator, as the case may be, will take any other action permitted to be taken by a holder under the indenture on behalf of a Euroclear participant or Clearstream Luxembourg customer only in accordance with its relevant rules and procedures.

Euroclear and Clearstream Luxembourg have agreed to the foregoing procedures in order to facilitate transfers of the Notes among participants of Euroclear and Clearstream Luxembourg. However, they are under no obligation to perform or continue to perform those procedures, and they may discontinue those procedures at any time.

Payment of Additional Amounts

We will, subject to the exceptions and limitations set forth below, pay as additional interest on the Notes such additional amounts as are necessary so that the net payment by us or our paying agent of the principal of and interest on the Notes to a person that is a United States Alien, after deduction for any present or future tax, assessment or governmental charge of the United States or a political subdivision or taxing authority thereof or therein, imposed by withholding with respect to the payment, will not be less than the amount that would have been payable in respect of the Notes had no withholding or deduction been required. As used herein, “United States Alien” means any person who, for United States federal income tax purposes, is a foreign corporation, a non-resident alien individual, a non-resident alien fiduciary of a foreign estate or trust, or a foreign partnership one or more of the members of which is, for United States federal income tax purposes, a foreign corporation, a non-resident alien individual or a non-resident alien fiduciary of a foreign estate or trust.

Our obligation to pay additional amounts shall not apply:

(1) to any tax, assessment or governmental charge that is imposed or withheld solely because the beneficial owner, or a fiduciary, settlor, beneficiary or member of the beneficial owner if the beneficial owner is an estate, trust or partnership, or a person holding a power over an estate or trust administered by a fiduciary holder:

(a) is or was present or engaged in a trade or business in the United States, has or had a permanent establishment in the United States, or has any other present or former connection with the United States or any political subdivision or taxing authority thereof or therein;

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(b) is or was a citizen or resident or is or was treated as a resident of the United States;

(c) is or was a foreign or domestic personal holding company, a passive foreign investment company or a controlled foreign corporation with respect to the United States or is or was a corporation that has accumulated earnings to avoid United States federal income tax;

(d) is or was a bank receiving interest described in Section 881(c)(3)(A) of the Internal Revenue Code of 1986, as amended (the “Code”); or

(e) is or was an actual or constructive owner of 10% or more of the total combined voting power of all classes of stock of AT&T entitled to vote;

(2) to any holder that is not the sole beneficial owner of the Notes, or a portion thereof, or that is a fiduciary or partnership, but only to the extent that the beneficial owner, a beneficiary or settlor with respect to the fiduciary, or a member of the partnership would not have been entitled to the payment of an additional amount had such beneficial owner, beneficiary, settlor or member received directly its beneficial or distributive share of the payment;

(3) to any tax, assessment or governmental charge that is imposed or withheld solely because the beneficial owner or any other person failed to comply with certification, identification or information reporting requirements concerning the nationality, residence, identity or connection with the United States of the holder or beneficial owner of the Notes, if compliance is required by statute, by regulation of the United States Treasury Department or by an applicable income tax treaty to which the United States is a party as a precondition to exemption from such tax, assessment or other governmental charge;

(4) to any tax, assessment or governmental charge that is imposed other than by deduction or withholding by AT&T or a paying agent from the payment;

(5) to any tax, assessment or governmental charge that is imposed or withheld solely because of a change in law, regulation, or administrative or judicial interpretation that is announced or becomes effective after the day on which the payment becomes due or is duly provided for, whichever occurs later;

(6) to an estate, inheritance, gift, sales, excise, transfer, wealth or personal property tax or any similar tax, assessment or governmental charge;

(7) to any tax, assessment or other governmental charge any paying agent (which term may include us) must withhold from any payment of principal of or interest on any Note, if such payment can be made without such withholding by any other paying agent; or

(8) in the case of any combination of the above items.

In addition, any amounts to be paid on the Notes will be paid net of any deduction or withholding imposed or required pursuant to Sections 1471 through 1474 of the Code, any current or future regulations or official interpretations thereof, any agreement entered into pursuant to Section 1471(b) of the Code, or any fiscal or regulatory legislation, rules or practices adopted pursuant to any intergovernmental agreement entered into in connection with the implementation of such Sections of the Code, and no additional amounts will be required to be paid on account of any such deduction or withholding.

The Notes are subject in all cases to any tax, fiscal or other law or regulation or administrative or judicial interpretation applicable. Except as specifically provided under this heading “—Payment of Additional Amounts” and under the heading “—Redemption Upon a Tax Event,” we do not have to make any payment with respect to any tax, assessment or governmental charge imposed by any government or a political subdivision or taxing authority.

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Any reference in the terms of the Notes to any amounts in respect of the Notes shall be deemed also to refer to any additional amounts which may be payable under this provision.

Redemption Upon a Tax Event

If (a) we become or will become obligated to pay additional amounts with respect to any Notes as described herein under the heading “—Payment of Additional Amounts” as a result of any change in, or amendment to, the laws (or any regulations or rulings promulgated thereunder) of the United States (or any political subdivision or taxing authority thereof or therein), or any change in, or amendments to, any official position regarding the application or interpretation of such laws, regulations or rulings, which change or amendment is announced or becomes effective, on or after September 9, 2025 or (b) a taxing authority of the United States takes an action on or after September 9, 2025, whether or not with respect to us or any of our affiliates, that results in a substantial probability that we will or may be required to pay such additional amounts, then we may, at our option, redeem, as a whole, but not in part, the Notes on any interest payment date on not less than 5 nor more than 40 calendar days’ prior notice, at a redemption price equal to 100% of their principal amount, together with interest accrued thereon to the date fixed for redemption. No redemption pursuant to (b) above may be made unless we shall have received an opinion of independent counsel to the effect that an act taken by a taxing authority of the United States results in a substantial probability that we will or may be required to pay the additional amounts described herein under the heading “—Payment of Additional Amounts” and we shall have delivered to the trustee a certificate, signed by a duly authorized officer, stating that based on such opinion we are entitled to redeem the Notes pursuant to their terms.

Further Issues

We may from time to time, without notice to or the consent of the holders of the Notes, create and issue further notes ranking equally and ratably with such Notes in all respects, or in all respects except for the payment of interest accruing prior to the issue date or except for the first payment of interest following the issue date of those further notes. Any further notes will have the same terms as to status, redemption or otherwise as, and will be fungible for United States federal income tax purposes with, the Notes. Any further notes shall be issued pursuant to a resolution of our board of directors, a supplement to the indenture, or under an officers’ certificate pursuant to the indenture.

Notices

Notices to holders of the Notes will be given only to the depositary, in accordance with its applicable policies as in effect from time to time.

Prescription Period

Any money that we deposit with the trustee or any paying agent for the payment of principal or any interest on any Note that remains unclaimed for two years after the date upon which the principal and interest are due and payable will be repaid to us upon our request unless otherwise required by mandatory provisions of any applicable unclaimed property law. After that time, unless otherwise required by mandatory provisions of any unclaimed property law, the holder of the Note will be able to seek any payment to which that holder may be entitled to collect only from us.

Governing Law

The Notes will be governed by and interpreted in accordance with the laws of the State of New York.

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UNITED STATES TAX CONSIDERATIONS

This section describes the material United States federal income tax consequences of owning the Notes we are offering. It applies to you only if you acquire Notes in the offering and you hold your Notes as capital assets for tax purposes. This discussion addresses only United States federal income taxation and does not discuss all of the tax consequences that may be relevant to you in light of your individual circumstances, including foreign, state or local tax consequences, estate and gift tax consequences, tax consequences arising under the Medicare contribution tax on net investment income, or the alternative minimum tax. This section does not apply to you if you are a member of a class of holders subject to special rules, such as:

This section is based on the Code, its legislative history, existing and proposed regulations under the Code, published rulings and court decisions, all as currently in effect. These laws are subject to change, possibly on a retroactive basis.

If a partnership (including any entity treated as a partnership for U.S. federal income tax purposes) holds the Notes, the United States federal income tax treatment of a partner will generally depend on the status of the partner and the tax treatment of the partnership. A partner in a partnership holding the Notes should consult its tax advisor with regard to the United States federal income tax treatment of an investment in the Notes.

Please consult your tax advisor concerning the consequences of owning these Notes, in your particular circumstances, under the Code and the laws of any other taxing jurisdiction.

United States Holders

This subsection describes the United States federal income tax consequences to a United States holder. You are a United States holder if you are the beneficial owner of a Note and you are, for United States federal income tax purposes:

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If you are not a United States holder, this subsection does not apply to you and you should refer to “—Non-United States Holders” below.

Payments of Interest. You will be taxed on interest on your Note as ordinary income at the time you receive the interest or when it accrues, depending on your method of accounting for tax purposes.

Cash Basis Taxpayers. If you are a taxpayer that uses the cash receipts and disbursements method of accounting for tax purposes, you must recognize income equal to the U.S. dollar value of the euro you receive on each interest payment date for your Notes, based on the exchange rate in effect on the date of receipt, regardless of whether you actually convert such euro received into U.S. dollars.

Accrual Basis Taxpayers. If you are a taxpayer that uses an accrual method of accounting for tax purposes, you may determine the amount of income that you recognize with respect to the euro you receive on each interest payment date by using one of two methods. Under the first method, you will determine the amount of income accrued based on the average U.S. dollar-euro exchange rate in effect during the interest accrual period or, with respect to an accrual period that spans two taxable years, that part of the period within the taxable year.

If you elect the second method, you would determine the amount of income accrued on the basis of the U.S. dollar-euro exchange rate in effect on the last day of the accrual period, or, in the case of an accrual period that spans two taxable years, the U.S. dollar-euro exchange rate in effect on the last day of the part of the period within the taxable year. Additionally, under this second method, if you receive a payment of interest within five business days of the last day of your accrual period or taxable year, you may instead translate the euro interest accrued into U.S. dollars at the U.S. dollar-euro exchange rate in effect on the day that you actually receive the interest payment. If you elect the second method it will apply to all debt instruments that you hold at the beginning of the first taxable year to which the election applies and to all debt instruments that you subsequently acquire (regardless of the foreign currency in which such debt instruments are denominated). You may not revoke this election without the consent of the Internal Revenue Service.

When you actually receive euro on an interest payment date, including a payment attributable to accrued but unpaid interest upon the sale or retirement of your Note, you will recognize ordinary income or loss measured by the difference, if any, between the exchange rate that you used to accrue such interest income and the exchange rate in effect on the date of receipt, regardless of whether you actually convert the euro received into U.S. dollars.

Purchase, Sale and Retirement of the Notes. Your tax basis in your Note will generally be the U.S. dollar cost, as defined below, of your Note. If you purchase your Note with euro, the U.S. dollar cost of your Note will generally be the U.S. dollar value of the euro purchase price on the date of purchase.

You will generally recognize gain or loss on the sale or retirement of your Note equal to the difference between the amount you realize on the sale or retirement, excluding any amounts attributable to accrued but unpaid interest on the Note (which will be treated as interest payments), and your tax basis in your Note. If you are an accrual basis taxpayer, the amount you realize will generally be the U.S. dollar value of the euro you receive on the date the Note is disposed of or retired, and if you are a cash basis taxpayer, or an accrual basis taxpayer and you so elect, because we expect that the Notes will be traded on an established securities market (within the meaning of the applicable Treasury regulations), you will determine the amount realized based on the U.S. dollar value of euro on the settlement date of the sale.

Such gain or loss will be capital gain or loss, except to the extent attributable to changes in exchange rates as described below. Capital gain of a noncorporate United States holder is generally taxed at preferential rates where the property is held for more than one year. You must treat any portion of the gain or loss that you recognize on the sale or retirement of a Note as ordinary income or loss to the extent attributable to changes in the U.S. dollar-euro exchange rate. However, you must take exchange gain or loss into account only to the extent of the total gain or loss you realize on the transaction.

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Exchange of Amounts in Euro. When you receive euro as interest on your Note or on the sale, retirement or other disposition of your Note, your tax basis in such euro will equal its U.S. dollar value when the interest is received or at the time of such sale, retirement or disposition. If you purchase euro, you generally will have a tax basis equal to the U.S. dollar value of the euro on the date of your purchase of such euro. If you sell or dispose of euro, including if you use euro to purchase Notes or you convert euro payments on the Notes to U.S. dollars, any gain or loss recognized generally will be ordinary income or loss.

Treasury Regulations Requiring Disclosure of Reportable Transactions

Applicable Treasury regulations require United States taxpayers to report certain transactions that give rise to a loss in excess of certain thresholds (a “Reportable Transaction”). Under these regulations, because the Notes are denominated in euro, a United States holder (or a non-United States holder that holds the Notes in connection with a U.S. trade or business) that recognizes a loss with respect to the Notes that is characterized as an ordinary loss due to changes in currency exchange rates (under any of the rules discussed above) would be required to report the loss on Internal Revenue Service Form 8886 (Reportable Transaction Statement) if the loss exceeds the thresholds set forth in the regulations. For individuals and trusts, this loss threshold is $50,000 in any single taxable year. For other types of taxpayers and other types of losses, the thresholds are higher. You should consult with your tax advisor regarding any tax filing and reporting obligations that may apply in connection with acquiring, owning and disposing of Notes.

Non-United States Holders

This subsection describes the United States federal income tax consequences to a non-United States holder. You are a non-United States holder if you are the beneficial owner of a Note and you are, for United States federal income tax purposes:

If you are a United States holder, this subsection does not apply to you.

Payments of Interest. Subject to the discussions of backup withholding and FATCA below, if you are a non-United States holder of a Note, interest on the Note paid to you is exempt from U.S. federal income tax, including withholding tax, if:

1. you do not actually or constructively own 10% or more of the total combined voting power of all classes of our stock entitled to vote,

2. you are not a controlled foreign corporation that is related to us through stock ownership,

3. the interest on the Notes is not effectively connected with your conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, is not attributable to a U.S. permanent establishment that you maintain), and

4. the United States payor does not have actual knowledge or reason to know that you are a United States person and:

a. you have furnished to the United States payor an Internal Revenue Service Form W-8BEN or Internal Revenue Service Form W-8BEN-E or an acceptable substitute form upon which you certify, under penalties of perjury, that you are a non-United States person,

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b. in the case of payments made outside the United States to you at an offshore account (generally, an account maintained by you at a bank or other financial institution at any location outside the United States), you have furnished to the United States payor documentation that establishes your identity and your status as the beneficial owner of the payment for United States federal income tax purposes and as a non-United States person,

c. the United States payor has received a withholding certificate (furnished on an appropriate Internal Revenue Service Form W-8 or an acceptable substitute form) from a person claiming to be:

i. a withholding foreign partnership (generally a foreign partnership that has entered into an agreement with the Internal Revenue Service to assume primary withholding responsibility with respect to distributions and guaranteed payments it makes to its partners),

ii. a qualified intermediary (generally a non-United States financial institution or clearing organization or a non-United States branch or office of a United States financial institution or clearing organization that is a party to a withholding agreement with the Internal Revenue Service), or

iii. a United States branch of a non-United States bank or of a non-United States insurance company, and the withholding foreign partnership, qualified intermediary or United States branch has received documentation upon which it may rely to treat the payment as made to a non-United States person that is, for United States federal income tax purposes, the beneficial owner of the payment on the Notes in accordance with U.S. Treasury regulations (or, in the case of a qualified intermediary, in accordance with its agreement with the Internal Revenue Service),

d. the United States payor receives a statement from a securities clearing organization, bank or other financial institution that holds customers’ securities in the ordinary course of its trade or business,

i. certifying to the United States payor under penalties of perjury that an Internal Revenue Service Form W-8BEN or Internal Revenue Service Form W-8BEN-E or an acceptable substitute form has been received from you by it or by a similar financial institution between it and you, and

ii. to which is attached a copy of the Internal Revenue Service Form W-8BEN or Internal Revenue Service Form W-8BEN-E or acceptable substitute form, or

e. the United States payor otherwise possesses documentation upon which it may rely to treat the payment as made to a non-United States person that is, for United States federal income tax purposes, the beneficial owner of the payment on the Notes in accordance with U.S. Treasury regulations; and

Sale, Exchange or Other Disposition of the Notes. If you are a non-United States holder of a Note, you generally will not be subject to U.S. federal income tax on gain realized on the sale, exchange or other disposition of such Note, unless:

FATCA Withholding

A 30% withholding tax (“FATCA withholding”) may be imposed on certain payments to you or to certain foreign financial institutions, investment funds and other non-U.S. persons receiving payments on your behalf if you or such persons fail to comply with certain information reporting requirements. Payments of interest that you

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receive in respect of the Notes could be affected by this withholding if you are subject to the FATCA information reporting requirements and fail to comply with them or if you hold such Notes through a non-U.S. person (e.g., a foreign bank or broker) that fails to comply with these requirements (even if payments to you would not otherwise have been subject to FATCA withholding). You should consult your own tax advisors regarding the relevant U.S. law and other official guidance on FATCA withholding.

We will not pay any additional amounts in respect of FATCA withholding, so if this withholding applies, you will receive significantly less than the amount that you would have otherwise received with respect to your Notes. Depending on your circumstances, you may be entitled to a refund or credit in respect of some or all of this withholding. However, even if you are entitled to have any such withholding refunded, the required procedures could be cumbersome and significantly delay the holder’s receipt of any amounts withheld.

Backup Withholding and Information Reporting

United States Holders

In general, if you are a noncorporate United States holder, the applicable withholding agent is required to report to the Internal Revenue Service all payments of principal and interest on your Note. In addition, the applicable withholding agent is required to report to the Internal Revenue Service any payment of proceeds of the sale of your Note before maturity within the United States. Additionally, backup withholding will apply to any payments if you fail to provide an accurate taxpayer identification number, or (in the case of interest payments) you are notified by the Internal Revenue Service that you have failed to report all interest and dividends required to be shown on your federal income tax returns.

Non-United States Holders

In general, if you are a non-United States holder, payments of principal or interest made by the applicable withholding agent to you will not be subject to backup withholding and information reporting, provided that the certification requirements described above under “—United States Tax Considerations—Non-United States Holders—Payments of Interest” are satisfied or you otherwise establish an exemption. However, the applicable withholding agent is required to report payments of interest on your Notes on Internal Revenue Service Form 1042-S even if the payments are not otherwise subject to information reporting requirements. In addition, payment of the proceeds from the sale of Notes effected at a United States office of a broker will not be subject to backup withholding and information reporting provided that:

1. an appropriate Internal Revenue Service Form W-8 or an acceptable substitute form upon which you certify, under penalties of perjury, that you are not a United States person, or

2. other documentation upon which it may rely to treat the payment as made to a non-United States person in accordance with U.S. Treasury regulations; or

If you fail to establish an exemption and the broker does not possess adequate documentation of your status as a non-United States person, the payments may be subject to information reporting and backup withholding. However, backup withholding will not apply with respect to payments made to an offshore account maintained by you unless the broker has actual knowledge that you are a United States person.

In general, payment of the proceeds from the sale of Notes effected at a foreign office of a broker will not be subject to information reporting or backup withholding. However, a sale effected at a foreign office of a broker will be subject to information reporting and backup withholding if:

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unless, in each case, the broker does not have actual knowledge or reason to know that you are a United States person and the documentation requirements described above (relating to a sale of Notes effected at a United States office of a broker) are met or you otherwise establish an exemption.

In addition, payment of the proceeds from the sale of Notes effected at a foreign office of a broker will be subject to information reporting if the broker is:

1. one or more of its partners are “U.S. persons”, as defined in U.S. Treasury regulations, who in the aggregate hold more than 50% of the income or capital interest in the partnership, or

2. such foreign partnership is engaged in the conduct of a United States trade or business, unless the broker does not have actual knowledge or reason to know that you are a United States person and the documentation requirements described above (relating to a sale of Notes effected at a United States office of a broker) are met or you otherwise establish an exemption. Backup withholding will apply if the sale is subject to information reporting and the broker has actual knowledge that you are a United States person.

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