T-MOBILE USA, INC. and T-MOBILE US, INC. and EACH OF THE SUBSIDIARY GUARANTORS FROM TIME TO TIME PARTY HERETO 5.300% SENIOR NOTES DUE 2035 TWENTY-SEVENTH SUPPLEMENTAL INDENTURE Dated as of March 27, 2025 DEUTSCHE BANK TRUST COMPANY AMERICAS as Trustee...

Exhibit 4.3

Execution Version

T-MOBILE USA, INC.

and

T-MOBILE US, INC.

and

EACH OF THE SUBSIDIARY GUARANTORS FROM TIME TO TIME PARTY HERETO

5.300% SENIOR NOTES DUE 2035

TWENTY-SEVENTH SUPPLEMENTAL INDENTURE

Dated as of March 27, 2025

DEUTSCHE BANK TRUST COMPANY AMERICAS

as Trustee

to

INDENTURE

Dated as of September 15, 2022

TABLE OF CONTENTS

EXHIBITS

i

TWENTY-SEVENTH SUPPLEMENTAL INDENTURE (this “Twenty-Seventh Supplemental Indenture”), dated as of March 27, 2025 (the “Series Issue Date”), among T-Mobile USA, Inc., a Delaware corporation (the “Issuer”), T-Mobile, US, Inc., a Delaware corporation (“Parent,” as a guarantor), and the other guarantors party hereto (together with Parent, the “Guarantors”) and Deutsche Bank Trust Company Americas, a New York banking corporation, as Trustee.

WHEREAS, the Issuer has heretofore executed and delivered an Indenture, dated as of September 15, 2022 (the “Base Indenture”), among the Issuer, Parent and the Trustee, providing for the issuance from time to time of one or more Series of the Issuer’s Notes;

WHEREAS, Section 2.01 of the Base Indenture permits the creation of the Notes of any Series with the terms and in the form permitted in Sections 2.02 of the Base Indenture to be established in a supplemental indenture to the Base Indenture;

WHEREAS, the Issuer has requested the Trustee to join with it and the Guarantors in the execution of this Twenty-Seventh Supplemental Indenture in order to supplement the Base Indenture by, among other things, establishing the forms and certain terms of a Series of Notes to be known as the Issuer’s “5.300% Senior Notes due 2035” and adding certain provisions thereto for the benefit of the Holders of the Notes of such Series;

WHEREAS, the Issuer has furnished the Trustee with a duly authorized and executed Company Order dated March 27, 2025 authorizing the execution of this Twenty-Seventh Supplemental Indenture and the issuance of the Notes established hereby; and

WHEREAS, all things necessary to make this Twenty-Seventh Supplemental Indenture a valid, binding and enforceable agreement of the Issuer, the Guarantors and the Trustee and a valid supplement to the Base Indenture have been done.

NOW, THEREFORE, the Issuer, the Guarantors and the Trustee agree as follows for the benefit of each other and for the equal and ratable benefit of the Holders of the Notes established hereby:

ARTICLE I

DEFINITIONS AND INCORPORATION BY REFERENCE

Section 1.01 Definitions.

The Base Indenture, as amended and supplemented in respect of the Notes by this Twenty-Seventh Supplemental Indenture is collectively referred to as the “Indenture.” All capitalized terms which are used herein and not otherwise defined herein are defined in the Base Indenture and are used herein with the same meanings as in the Base Indenture. If a capitalized term is defined in both the Base Indenture and this Twenty-Seventh Supplemental Indenture, the definition in this Twenty-Seventh Supplemental Indenture shall apply to the Notes established hereby (and any Note Guarantee in respect thereof).

Section 1.02 Other Definitions.

Section 1.03 Rules of Construction.

Unless the context otherwise requires:

(1) a term has the meaning assigned to it;

(2) an accounting term not otherwise defined has the meaning assigned to it in accordance with GAAP;

(3) “or” is not exclusive;

(4) words in the singular include the plural, and in the plural include the singular;

(5) “will” shall be interpreted to express a command;

(6) provisions apply to successive events and transactions;

(7) “including” means “including, without limitation”;

(8) references to sections of or rules under the Securities Act will be deemed to include substitute, replacement or successor sections or rules adopted by the SEC from time to time; and

(9) the phrases “in writing” or “written” as used herein shall be deemed to include PDFs, e-emails and other electronic means of Transmission, unless otherwise indicated.

ARTICLE II

THE NOTES

Section 2.01 Creation of the Notes; Designations.

In accordance with Section 2.01 of the Base Indenture, the Issuer hereby creates a Series of Notes issued pursuant to the Indenture. The Notes of this Series shall be known and designated as the “5.300% Senior Notes due 2035” of the Issuer. The Notes of this Series shall be entitled to the benefits of the Note Guarantee of each Guarantor signatory hereto, or that may hereafter execute a supplemental indenture in accordance with Section 10.03 of the Base Indenture, each such Note Guarantee to be governed by Article X of the Base Indenture (including, without limitation, the provisions for release of such Note Guarantee in respect of the Notes of this Series pursuant to Section 10.04 of the Base Indenture).

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Section 2.02 Forms Generally.

(a) General. The Notes of this Series and the Trustee’s certificate of authentication will be substantially in the form of Exhibit A hereto. The Notes of this Series may have notations, legends or endorsements required by law, stock exchange rule or usage. Each Note of this Series will be dated the date of its authentication. The Notes of this Series shall be in minimum denominations of $2,000 and integral multiples of $1,000.

The terms and provisions contained in the Notes of this Series will constitute, and are hereby expressly made, a part of this Twenty-Seventh Supplemental Indenture and the Issuer, the Guarantors and the Trustee, by their execution and delivery of this Twenty-Seventh Supplemental Indenture, expressly agree to such terms and provisions and to be bound thereby. However, to the extent any provision of any such Note conflicts with the express provisions of this Twenty-Seventh Supplemental Indenture, the provisions of this Twenty-Seventh Supplemental Indenture shall govern and be controlling.

(b) Global Notes. Notes of this Series issued in global form will be substantially in the form of Exhibit A hereto (including the Global Note Legend thereon and the “Schedule of Exchanges of Interests in the Global Note” attached thereto). Notes of this Series issued in definitive form will be substantially in the form of Exhibit A hereto (but without the Global Note Legend thereon and without the “Schedule of Exchanges of Interests in the Global Note” attached thereto). Each Global Note will represent such of the outstanding Notes of this Series as will be specified therein and each shall provide that it represents the aggregate principal amount of outstanding Notes of this Series from time to time endorsed thereon and that the aggregate principal amount of outstanding Notes of this Series represented thereby may from time to time be reduced or increased, as appropriate, to reflect exchanges and redemptions. Any endorsement of a Global Note to reflect the amount of any increase or decrease in the aggregate principal amount of outstanding Notes of this Series represented thereby will be made by the Trustee or the Notes Custodian, at the direction of the Trustee, in accordance with instructions given by the Holder thereof.

Section 2.03 Title and Terms of Notes.

The aggregate principal amount of Notes of this Series which shall be authenticated and delivered on the Series Issue Date under the Indenture shall be $1,000,000,000; provided, however, that the Issuer from time to time, without giving notice to or seeking the consent of the Holders of Notes of this Series, may issue additional notes (the “Additional Notes”) in any amount having the same terms as the Notes of this Series in all respects, except for the issue date, the issue price, the initial interest payment date and rights under a related registration rights agreement, if any. Any such Additional Notes shall be authenticated by the Trustee upon receipt of a Company Order to that effect, and when so authenticated, will constitute “Notes” for all

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purposes of the Indenture and will (together with all other Notes of this Series issued under the Indenture) constitute a single Series of Notes under the Indenture; provided that if such Additional Notes are not fungible with the Notes of this Series for U.S. federal income tax purposes, as applicable, as determined by the Issuer, such Additional Notes may have a separate CUSIP number.

(a) The Notes of this Series issued on the Series Issue Date will be issued at an issue price of 99.890% of the principal amount thereof.

(b) The principal amount of the Notes of this Series is due and payable in full as set forth in Exhibit A.

(c) The rate or rates at which the Notes of this Series shall bear interest, the date or dates from which such interest shall accrue, the interest payment dates on which any such interest shall be payable and the regular record date for any interest payable on any interest payment date, in each case, shall be as set forth in the form of the Note as set forth in Exhibit A.

(d) Other than as provided in Article III of this Twenty-Seventh Supplemental Indenture, the Notes of this Series shall not be redeemable.

(e) The Notes of this Series will initially be evidenced by one or more Global Notes issued in the name of Cede & Co., as nominee of The Depository Trust Company.

Section 2.04 Agreement to Guarantee.

The Guarantors hereby agree, jointly and severally, to unconditionally guarantee the Issuer’s obligations under the Notes of this Series and the Indenture on the terms and subject to the conditions set forth in the Indenture including but not limited to ARTICLE X of the Base Indenture.

ARTICLE III

REDEMPTION AND PREPAYMENT

Section 3.01 Optional Redemption.

The Notes of this Series may be redeemed, in whole, or from time to time in part, subject to the conditions and at the redemption prices set forth in Section 5 of the form of Note set forth in Exhibit A hereto, which are hereby incorporated by reference and made part of this Twenty-Seventh Supplemental Indenture, together with accrued and unpaid interest, if any, thereon to, but not including, the redemption date, and in accordance with Article III of the Base Indenture.

ARTICLE IV

NOTE GUARANTEES

Section 4.01 Note Guarantees.

Subject to Section 10.04 of the Base Indenture, the Notes of this Series shall be guaranteed (i) initially by Parent and any Wholly-Owned Subsidiary of the Issuer that (x) is not an Excluded Subsidiary and (y) is an obligor under the Credit Agreement and (ii) by any future direct or indirect Subsidiary of Parent that is not a Subsidiary of the Issuer or any other Guarantor that directly or indirectly owns Capital Stock of the Issuer.

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ARTICLE V

MISCELLANEOUS

Section 5.01 Effect of the Twenty-Seventh Supplemental Indenture.

(a) This Twenty-Seventh Supplemental Indenture is a supplemental indenture within the meaning of Section 2.02 of the Base Indenture, and the Base Indenture shall (notwithstanding Section 12.12 thereof or Section 5.04 hereof) be read together with this Twenty-Seventh Supplemental Indenture and shall have the same effect over the Notes of this Series, in the same manner as if the provisions of the Base Indenture and this Twenty-Seventh Supplemental Indenture were contained in the same instrument.

(b) In all other respects, the Base Indenture is confirmed by the parties hereto as supplemented by the terms of this Twenty-Seventh Supplemental Indenture.

Section 5.02 Governing Law.

THIS TWENTY-SEVENTH SUPPLEMENTAL INDENTURE AND THE NOTES OF THIS SERIES WILL BE GOVERNED BY THE LAWS OF THE STATE OF NEW YORK.

Section 5.03 Waiver of Jury Trial.

EACH PARTY HERETO HEREBY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY RIGHT IT MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY LITIGATION DIRECTLY OR INDIRECTLY ARISING OUT OF, UNDER OR IN CONNECTION WITH THIS TWENTY-SEVENTH SUPPLEMENTAL INDENTURE.

Section 5.04 No Adverse Interpretation of Other Agreements.

Subject to Section 5.01, this Twenty-Seventh Supplemental Indenture may not be used to interpret any other indenture, loan or debt agreement of the Issuer, Parent or its Subsidiaries or of any other Person. Subject to Section 5.01, any such other indenture, loan or debt agreement may not be used to interpret this Twenty-Seventh Supplemental Indenture.

Section 5.05 Successors.

All agreements of the Issuer in this Twenty-Seventh Supplemental Indenture and the Notes of this Series will bind its successors. All agreements of the Trustee in this Twenty-Seventh Supplemental Indenture will bind its successors. All agreements of each Guarantor in this Twenty-Seventh Supplemental Indenture will bind its successors, except as otherwise provided in Section 10.04 of the Base Indenture.

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Section 5.06 Severability.

In case any provision in this Twenty-Seventh Supplemental Indenture or in the Notes of this Series is invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions will not in any way be affected or impaired thereby.

Section 5.07 Counterparts.

This Twenty-Seventh Supplemental Indenture may be executed in any number of counterparts and by the parties hereto in separate counterparts, each of which when so executed will be deemed to be an original and all of which taken together will constitute one and the same agreement. The exchange of copies of this Twenty-Seventh Supplemental Indenture and of signature pages by electronic (including PDF) transmission shall constitute effective execution and delivery of this Twenty-Seventh Supplemental Indenture as to the parties hereto and may be used in lieu of the original Twenty-Seventh Supplemental Indenture for all purposes. Signatures of the parties hereto transmitted by electronic (including PDF) transmission shall be deemed to be their original signatures for all purposes.

Section 5.08 Table of Contents, Headings, etc.

The Table of Contents and headings of the Articles and Sections of this Twenty-Seventh Supplemental Indenture have been inserted for convenience of reference only, are not to be considered a part of this Twenty-Seventh Supplemental Indenture and will in no way modify or restrict any of the terms or provisions hereof.

Section 5.09 Beneficiaries of this Twenty-Seventh Supplemental Indenture.

Nothing in this Twenty-Seventh Supplemental Indenture or in the Notes of this Series, expressed or implied, shall give to any Person, other than the parties hereto and their successors hereunder, and the Holders of the Notes of this Series, any benefit or any legal or equitable right, remedy or claim under this Twenty-Seventh Supplemental Indenture.

Section 5.10 No Personal Liability of Directors, Officers, Employees and Stockholders.

No past, present or future director, officer, member, manager, partner, employee, incorporator or stockholder of the Issuer or any Guarantor, as such, will have any liability for any obligations of the Issuer or the Guarantors under the Notes of this Series, this Twenty-Seventh Supplemental Indenture, the Note Guarantees, or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each Holder of the Notes of this Series by accepting a Note of this Series waives and releases all such liability. The waiver and release are part of the consideration for issuance of the Notes of this Series.

Section 5.11 The Trustee.

The Trustee shall not be responsible or liable for the validity or sufficiency of, or the recitals in, this Twenty-Seventh Supplemental Indenture and all of the provisions contained in the Base Indenture in respect of the rights, privileges, immunities, powers and duties of the Trustee and the Agents shall be applicable in respect of the Notes of this Series and of this Twenty-Seventh Supplemental Indenture as fully and with like effect as set forth in full herein.

[Signatures on following page]

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IN WITNESS WHEREOF, the parties hereto have caused this Twenty-Seventh Supplemental Indenture to be duly executed, all as of the date first above written.

[Twenty-Seventh Supplemental Indenture]

[Twenty-Seventh Supplemental Indenture]

[Twenty-Seventh Supplemental Indenture]

[Twenty-Seventh Supplemental Indenture]

Exhibit A

[Form of Face of Initial Note]

[Insert the Global Notes Legend, if applicable pursuant to the provisions of the Indenture]

THIS NOTE IS A GLOBAL NOTE WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF THE DEPOSITARY OR A NOMINEE OF THE DEPOSITARY. THIS NOTE IS EXCHANGEABLE FOR NOTES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITARY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE, AND MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY, BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH A SUCCESSOR DEPOSITARY.

[Insert Restricted Notes Legend, if applicable pursuant to the provisions of the Indenture]

THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR THE SECURITIES LAWS OF ANY STATE OR OTHER JURISDICTION AND NEITHER THIS SECURITY NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO, SUCH REGISTRATION. THE HOLDER OF THIS SECURITY, BY ITS ACCEPTANCE HEREOF, AGREES ON ITS OWN BEHALF AND ON BEHALF OF ANY INVESTOR ACCOUNT FOR WHICH IT HAS PURCHASED SECURITIES, TO OFFER, SELL OR OTHERWISE TRANSFER SUCH SECURITY, PRIOR TO THE DATE (THE “RESALE RESTRICTION TERMINATION DATE”) THAT IS [IN THE CASE OF RULE 144A NOTES: ONE YEAR AFTER THE LATER OF THE ORIGINAL ISSUE DATE HEREOF, THE ORIGINAL ISSUE DATE OF THE ISSUANCE OF ANY ADDITIONAL NOTES AND THE LAST DATE ON WHICH THE ISSUER OR ANY AFFILIATE OF THE ISSUER WAS THE OWNER OF THIS SECURITY (OR ANY PREDECESSOR OF SUCH SECURITY),] [IN THE CASE OF REGULATION S NOTES: 40 DAYS AFTER THE LATER OF THE ORIGINAL ISSUE DATE HEREOF AND THE DATE ON WHICH THIS SECURITY (OR ANY PREDECESSOR OF SUCH SECURITY) WAS FIRST OFFERED TO PERSONS OTHER THAN DISTRIBUTORS (AS DEFINED IN RULE 902 OF REGULATION S) IN RELIANCE ON REGULATION S] ONLY (A)(1) TO THE ISSUER OR ANY SUBSIDIARY THEREOF, (2) PURSUANT TO A REGISTRATION STATEMENT THAT HAS BEEN DECLARED EFFECTIVE UNDER THE SECURITIES ACT, (3) FOR SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO RULE 144A UNDER THE SECURITIES ACT, TO A PERSON IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN RULE 144A PURCHASING FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A, (4) IN AN OFFSHORE TRANSACTION COMPLYING WITH RULE 903 OR RULE 904 OF

Exhibit A-1

REGULATION S UNDER THE SECURITIES ACT, (5) TO AN INSTITUTIONAL “ACCREDITED INVESTOR” WITHIN THE MEANING OF RULE 501 OF REGULATION D UNDER THE SECURITIES ACT IN A TRANSACTION EXEMPT FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT OR (6) PURSUANT TO ANOTHER AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND (B) IN ACCORDANCE WITH ALL APPLICABLE SECURITIES LAWS OF THE STATES OF THE UNITED STATES AND OTHER JURISDICTIONS. THIS LEGEND WILL BE REMOVED UPON THE REQUEST OF THE HOLDER AFTER THE RESALE RESTRICTION TERMINATION DATE.

BY ITS ACQUISITION OF THIS SECURITY OR ANY INTEREST HEREIN, THE HOLDER WILL BE DEEMED TO HAVE REPRESENTED AND WARRANTED THAT EITHER (I) NO PORTION OF THE ASSETS USED BY SUCH HOLDER TO ACQUIRE OR HOLD THIS NOTE OR ANY INTEREST HEREIN CONSTITUTES THE ASSETS OF ANY (A) EMPLOYEE BENEFIT PLAN THAT IS SUBJECT TO TITLE I OF THE U.S. EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974, AS AMENDED (“ERISA”), (B) PLAN, INDIVIDUAL RETIREMENT ACCOUNT OR OTHER ARRANGEMENT THAT IS SUBJECT TO SECTION 4975 OF THE U.S. INTERNAL REVENUE CODE OF 1986, AS AMENDED (THE “CODE”) OR PROVISIONS UNDER ANY OTHER FEDERAL, STATE, LOCAL, NON-U.S. OR OTHER LAWS OR REGULATIONS THAT ARE SIMILAR TO SUCH PROVISIONS OF ERISA OR THE CODE (COLLECTIVELY, “SIMILAR LAWS”), OR (C) ENTITY WHOSE UNDERLYING ASSETS ARE CONSIDERED TO INCLUDE “PLAN ASSETS” (WITHIN THE MEANING OF 29 C.F.R. SECTION 2510.3-101 (AS MODIFIED BY SECTION 3(42) OF ERISA) AND ANY SIMILAR LAWS) OF ANY SUCH PLAN, ACCOUNT OR ARRANGEMENT DESCRIBED IN CLAUSE (A) OR (B) ABOVE (EACH OF (A), (B) AND (C), A “PLAN”), OR (II)(A) THE ACQUISITION, HOLDING AND SUBSEQUENT DISPOSITION OF THIS SECURITY OR ANY INTEREST HEREIN WILL NOT CONSTITUTE A NON-EXEMPT PROHIBITED TRANSACTION UNDER SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE OR A SIMILAR VIOLATION UNDER ANY APPLICABLE SIMILAR LAWS AND (B) NONE OF THE ISSUER, THE APPLICABLE INITIAL PURCHASER(S) OF THE SECURITY NOR ANY OF THEIR AFFILIATES, IS, BY HAVING MADE ANY ORAL OR WRITTEN STATEMENT REGARDING THE SECURITY, UNDERTAKING TO PROVIDE IMPARTIAL INVESTMENT ADVICE, OR TO GIVE ADVICE IN A FIDUCIARY CAPACITY, IN CONNECTION WITH THE PLAN’S PURCHASE, HOLDING OR DISPOSITION OF THE SECURITY.

[Insert Additional Restricted Notes Legend for Notes Offered in Reliance on Regulation S, if applicable pursuant to the provisions of the Indenture]

BY ITS ACQUISITION HEREOF, THE HOLDER HEREOF REPRESENTS THAT IT IS NOT A U.S. PERSON NOR IS IT PURCHASING FOR THE ACCOUNT OF A U.S. PERSON AND IS ACQUIRING THIS SECURITY IN AN OFFSHORE TRANSACTION IN ACCORDANCE WITH REGULATION S UNDER THE SECURITIES ACT.

[Insert Definitive Notes Legend, if applicable pursuant to the provisions of the Indenture]

Exhibit A-2

IN CONNECTION WITH ANY TRANSFER, THE HOLDER WILL DELIVER TO THE REGISTRAR AND TRANSFER AGENT SUCH CERTIFICATES AND OTHER INFORMATION AS SUCH TRANSFER AGENT MAY REASONABLY REQUIRE TO CONFIRM THAT THE TRANSFER COMPLIES WITH THE FOREGOING RESTRICTIONS.

[Restricted Notes Legend for Definitive Notes, if applicable pursuant to the provisions of the Indenture]

THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR THE SECURITIES LAWS OF ANY STATE OR OTHER JURISDICTION. NEITHER THIS SECURITY NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO, SUCH REGISTRATION.

Exhibit A-3

CUSIP [  ]

ISIN [  ]

[RULE 144A] [REGULATION S] [GLOBAL] NOTE

5.300% Senior Notes due 2035

T-MOBILE USA, INC.

promises to pay to ___________________ or registered assigns, the principal sum [set forth on the Schedule of Exchanges of Interests in the Global Note attached hereto]¹ [__________________ DOLLARS]² on May 15, 2035.

Interest Payment Dates: May 15 and November 15.

Record Dates: May 1 and November 1.

Additional provisions of this Note are set forth on the other side of this Note.

Exhibit A-4

Dated: ____________

T-MOBILE USA, INC.

Exhibit A-5

This is one of the Notes referred to

in the within-mentioned Indenture:

DEUTSCHE BANK TRUST COMPANY AMERICAS,

as Trustee

Exhibit A-6

[Form of Reverse Side of Initial Note]

5.300% Senior Notes due 2035 (the “Notes”)

Capitalized terms used herein have the meanings assigned to them in the Indenture referred to below unless otherwise indicated.

(1) INTEREST.

Interest (computed on the basis of a 360-day year consisting of twelve 30-day months) shall accrue on the principal amount of this Note from and including March 27, 2025 until maturity at a rate per annum equal to 5.300%.

The Issuer promises to pay interest semi-annually in arrears on May 15 and November 15 of each year, or if any such day is not a Business Day, on the next succeeding Business Day (each, an “Interest Payment Date”). Interest on the Notes will accrue from the most recent date to which interest has been paid or, if no interest has been paid, from the date of issuance; provided that if there is no existing Default in the payment of interest, and if this Note is authenticated between a record date referred to on the face hereof and the next succeeding Interest Payment Date, interest shall accrue from such next succeeding Interest Payment Date; provided further that the first Interest Payment Date shall be May 15, 2025. If an interest payment date or the maturity date falls on a day that is not a Business Day, the related payment of principal or interest will be made on the next succeeding Business Day as if made on the date the payment was due, and no interest shall accrue for the intervening period.

(2) METHOD OF PAYMENT.

The Issuer will pay interest on the Notes (except defaulted interest) to the Persons who are registered Holders of Notes at the close of business on the May 1 or November 1 next preceding the Interest Payment Date, even if such Notes are canceled after such record date and on or before such Interest Payment Date, except as provided in Section 2.14 of the Base Indenture with respect to defaulted interest. The Notes will be payable as to principal, premium, if any, and interest at the office or agency of the Issuer maintained for such purpose within the City and State of New York, or, at the option of the Issuer, payment of interest may be made by check mailed to the Holders at their addresses set forth in the books and records of the Registrar; provided that payment by wire transfer of immediately available funds will be required with respect to principal of and interest and premium, if any, on, all Global Notes and all other Notes the Holders of which will have provided wire transfer instructions to the Issuer or the Paying Agent. Such payment will be in such money of the United States of America as at the time of payment is legal tender for payment of public and private debts. [The Holder of a Definitive Note is not required to surrender such Definitive Note to the Trustee in order to receive payment of principal at maturity. Such Definitive Note, after payment has been made, shall be cancelled without the requirement of presentation.]³

Exhibit A-7

(3) PAYING AGENT AND REGISTRAR.

Initially, Deutsche Bank Trust Company Americas, the Trustee under the Indenture, will act as Paying Agent and Registrar. The Issuer may change any Paying Agent or Registrar without notice to any Holder. The Issuer or any of its Subsidiaries may act in any such capacity.

(4) INDENTURE.

The Issuer issued the Notes pursuant to an Indenture dated as of September 15, 2022 (the “Base Indenture”) among the Issuer, Parent and the Trustee, as amended and supplemented with respect to the Notes by the Twenty-Seventh Supplemental Indenture dated as of March 27, 2025 (the “Twenty-Seventh Supplemental Indenture”; the Base Indenture, as amended and supplemented with respect to the Notes by the Twenty-Seventh Supplemental Indenture, the “Indenture”).

The terms of the Notes include those stated in the Indenture and those made part of the Indenture by reference to the Trust Indenture Act. The Notes are subject to all such terms, and Holders are referred to the Indenture and to the Trust Indenture Act for a statement of such terms. To the extent any provision of this Note conflicts with the express provisions of the Indenture, the provisions of the Indenture shall govern and be controlling. The Notes are senior unsecured, unsubordinated obligations of the Issuer. The Indenture does not limit the aggregate principal amount of Notes that may be issued thereunder.

The Issuer’s obligations under the Notes are unconditionally guaranteed on a senior unsecured basis, to the extent set forth in the Indenture, by each of the Guarantors to the extent set forth in the Indenture.

(5) OPTIONAL REDEMPTION.

Prior to February 15, 2035 (the “Par Call Date”), the Issuer may redeem the Notes at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

plus, in either case, accrued and unpaid interest thereon to the redemption date.

On or after the Par Call Date, the Issuer may redeem the Notes, in whole or in part, at any time or from time to time, at a redemption price equal to 100% of the principal amount of the Notes being redeemed plus accrued and unpaid interest thereon to the redemption date.

Exhibit A-8

“Treasury Rate” means, with respect to any redemption date, the yield determined by the Issuer in accordance with the following two paragraphs.

The Treasury Rate shall be determined by the Issuer after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third business day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily)—H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities–Treasury constant maturities–Nominal” (or any successor caption or heading). In determining the Treasury Rate, the Issuer shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields – one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life – and shall interpolate to the Par Call Date, on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

If on the third business day preceding the redemption date H.15 or any successor designation or publication is no longer published, the Issuer shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second business day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date, but there are two or more United States Treasury securities with a maturity date equally distant from such Par Call Date, one with a maturity date preceding such Par Call Date, and one with a maturity date following such Par Call Date, the Issuer shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date, or two or more United States Treasury securities meeting the criteria of the preceding sentence, the Issuer shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

The Issuer’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error.

Exhibit A-9

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the depositary’s procedures) at least 10 days but not more than 60 days before the redemption date to each holder of Notes to be redeemed.

The Trustee shall have no responsibility for calculating the redemption price for the Notes.

Unless the Issuer defaults in the payment of the redemption price, interest will cease to accrue on the Notes or portions thereof called for redemption on the applicable redemption date. At or before 10:00 a.m. (New York time) on the redemption date, the Issuer will deposit with the Trustee or a paying agent money sufficient to pay the redemption price of and accrued interest on the Notes to be redeemed on such date. If less than all of the Notes are to be redeemed, the Notes to be redeemed shall be selected in accordance with the procedures of DTC.

For the avoidance of doubt, the requirement to pay any Make-Whole Premium shall not arise in connection with any recovery of amounts due as a result of any breach of any covenant contained in the Indenture or the applicable Notes except where the transaction resulting in such breach was consummated with the intent to breach such covenant.

(6) MANDATORY REDEMPTION.

The Issuer is not required to make mandatory redemption or sinking fund payments with respect to the Notes.

(7) NOTICE OF REDEMPTION.

Notice of redemption will be sent at least 10 days but not more than 60 days before the redemption date to each Holder whose Notes are to be redeemed, except that redemption notices may be sent or mailed more than 60 days prior to a redemption date if the notice is issued in connection with a defeasance of the Notes or a satisfaction and discharge of the Indenture. Notes in denominations larger than $2,000 may be redeemed in part but only in whole multiples of $1,000, unless all of the Notes held by a Holder are to be redeemed. In connection with any redemption of Notes, any such notice of redemption may, at the Issuer’s discretion, state that such redemption is subject to one or more conditions precedent, including, but not limited to, completion of an equity offering, other offering, issuance of Indebtedness or other corporate transaction or event. In addition, if such notice of redemption is subject to satisfaction of one or more conditions precedent, such notice may state that, in the Issuer’s discretion, the redemption date may be delayed until such time as any or all such conditions shall be satisfied (or waived by the Issuer in its sole discretion), or such redemption may not occur and such notice may be rescinded in the event that any or all such conditions shall not have been satisfied (or waived by the Issuer in its sole discretion) by the redemption date (whether the original redemption date or the redemption date so delayed).

Exhibit A-10

(8) DENOMINATIONS, TRANSFER, EXCHANGE.

The Notes are in registered form without coupons in minimum denominations of $2,000 and integral multiples of $1,000. The transfer of Notes may be registered and Notes may be exchanged as provided in the Indenture. The Registrar and the Trustee may require a Holder, among other things, to furnish appropriate endorsements and transfer documents and the Issuer may require a Holder to pay any taxes and fees required by law or permitted by the Indenture. The Issuer need not exchange or register the transfer or exchange of any Note or portion of a Note selected for redemption, except for the unredeemed portion of any Note being redeemed in part. Also, the Issuer need not exchange or register the transfer of any Notes (i) for a period beginning at the opening of business 15 days immediately preceding the sending of notice of redemption of Notes selected for redemption and ending at the close of business on the day such notice is sent or (ii) during the period between a record date and the corresponding Interest Payment Date.

(9) PERSONS DEEMED OWNERS. The registered Holder of a Note may be treated as its owner for all purposes.

(10) AMENDMENT, SUPPLEMENT AND WAIVER. The Indenture, the Notes and the Note Guarantees may be amended, supplemented or waived as provided in Article IX of the Base Indenture.

(11) DEFAULTS AND REMEDIES. If an Event of Default occurs (other than an Event of Default relating to certain events of bankruptcy or insolvency of the Issuer, any of its Significant Subsidiaries or any group of Subsidiaries that, taken together, would constitute a Significant Subsidiary) and is continuing, the Trustee or the Holders of at least 30% in aggregate principal amount of the outstanding Notes, in each case, by notice to the Issuer, may declare the principal of, premium, if any, and accrued but unpaid interest, if any, on all the Notes to be due and payable; provided that no such declaration may be made with respect to or as a result of any action taken, and reported publicly or to holders of Notes, more than two years prior to such declaration. If an Event of Default relating to certain events of bankruptcy or insolvency of the Issuer, any of its Significant Subsidiary or any group of Subsidiaries that, taken together, would constitute a Significant Subsidiary occurs, the principal of, premium, if any, and interest on all the Notes shall become immediately due and payable without any declaration or other act on the part of the Trustee or any Holders. Under certain circumstances, the Holders of a majority in principal amount of the outstanding Notes may rescind any such acceleration with respect to the Notes and its consequences. The requirement to pay any Make-Whole Premium shall not arise in connection with any recovery of amounts due as a result of any breach of any covenant contained in the Indenture, this Supplemental Indenture or the applicable Notes except where the transaction resulting in such breach was consummated with the intent to breach such covenant.

(12) TRUSTEE DEALINGS WITH ISSUER. The Trustee, in its individual or any other capacity, may become the owner or pledgee of Notes and may otherwise deal with the Issuer or any Affiliate of the Issuer with the same rights it would have if it were not Trustee.

(13) NO RECOURSE AGAINST OTHERS. No past, present or future director, officer, member, manager, partner, employee, incorporator or stockholder of the Issuer or any Guarantor, as such, will have any liability for any obligations of the Issuer or the Guarantors under the Notes, the Indenture, the Note Guarantees or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each Holder by accepting a Note waives and releases all such liability. The waiver and release are part of the consideration for the issuance of the Notes.

Exhibit A-11

(14) AUTHENTICATION. This Note will not be valid until authenticated by the manual, facsimile or electronic (including PDF) signature of the Trustee or an authenticating agent.

(15) ABBREVIATIONS. Customary abbreviations may be used in the name of a Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT (= tenants by the entireties), JT TEN (= joint tenants with right of survivorship and not as tenants in common), CUST (= Custodian), and U/G/M/A (= Uniform Gifts to Minors Act).

(16) CUSIP NUMBERS. Pursuant to a recommendation promulgated by the Committee on Uniform Security Identification Procedures, the Issuer has caused CUSIP numbers to be printed on the Notes and the Trustee may use CUSIP numbers in notices of redemption as a convenience to Holders. No representation is made as to the accuracy of such numbers either as printed on the Notes or as contained in any notice of redemption, and reliance may be placed only on the other identification numbers placed thereon. No redemption will be affected by any defect in or omission of such numbers.

(17) GOVERNING LAW. THIS NOTE WILL BE GOVERNED BY THE LAWS OF THE STATE OF NEW YORK.

The Issuer will furnish to any Holder upon written request and without charge a copy of the Indenture. Requests may be made to:

T-Mobile USA, Inc.

▇▇▇▇▇ ▇▇ ▇▇▇▇ ▇▇▇▇▇▇

Bellevue, Washington 98006

Attention: General Counsel

Fax: (▇▇▇) ▇▇▇-▇▇▇▇

Exhibit A-12

ASSIGNMENT FORM

To assign this Note, fill in the form below:

(I) or (we) assign and transfer this Note to:                                   

(Insert assignee’s legal name)             

(Insert assignee’s soc. sec. or tax I.D. no.)

(Print or type assignee’s name, address and zip code)

and irrevocably appoint to transfer this Note on the books of the Issuer. The agent may substitute another to act for him.

Date:           

Your Signature:         

(Sign exactly as your name appears on the face of this Note)

Signature Guarantee*:      

Exhibit A-13

SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL NOTE*

The initial outstanding principal amount of this Global Note is $[_________].

The following exchanges of a part of this Global Note for an interest in another Global Note or for a Definitive Note, or exchanges of a part of another Global Note or Definitive Note for an interest in this Global Note, have been made: