Exhibit 4.3

FOURTH SUPPLEMENTAL INDENTURE

6.500% SENIOR NOTES DUE 2029

Fourth Supplemental Indenture (this “Supplemental Indenture”), dated as of August 4, 2025, among Windstream Services, LLC, a Delaware limited liability company (the “Successor Issuer”), Uniti Group Finance 2019 Inc., a Delaware corporation (“Uniti Group Finance”) and CSL Capital, LLC, a Delaware limited liability company (“CSL Capital,” and together with Uniti Group Finance, the “Uniti Issuers”; the Uniti Issuers together with the Successor Issuer are hereinafter collectively referred to as the “Issuers”), Uniti Group Inc., a Delaware corporation (formerly known as Windstream Parent Inc.) (the “New Parent”), Uniti Group LLC, a Delaware limited liability company (formerly known as Uniti Group Inc.), the guarantors listed under “Existing Subsidiary Guarantors” on the signature pages hereto (the “Existing Guarantors”), the subsidiaries of the Successor Issuer listed under “New Subsidiary Guarantors” on the signature pages hereto (each a “New Guaranteeing Subsidiary” and, collectively, the “New Guaranteeing Subsidiaries”; the New Guaranteeing Subsidiaries together with the Existing Guarantors shall comprise the “Subsidiary Guarantors” as such term is defined in the Indenture (as defined below)) and Deutsche Bank Trust Company Americas, a New York banking corporation, as trustee (the “Trustee”).

W I T N E S S E T H

WHEREAS, Uniti Group LP, a Delaware limited partnership (the “Predecessor Issuer”), the Uniti Issuers and the Existing Guarantors have heretofore executed and delivered to the Trustee an indenture (as amended, supplemented or otherwise modified through the date hereof, the “Indenture”), dated as of February 2, 2021, providing for the issuance of 6.500% Senior Notes due 2029 (the “Notes”);

Successor Issuer:

WHEREAS, the Predecessor Issuer has merged with and into the Successor Issuer, with the Successor Issuer surviving the merger;

WHEREAS, Section 5.01 of the Indenture contemplates that the Successor Issuer shall execute and deliver a supplemental indenture pursuant to which the Successor Issuer shall expressly assume all obligations of the Predecessor Issuer under the Indenture and the Notes;

WHEREAS, pursuant to Section 5.01 of the Indenture, upon the merger of the Predecessor Issuer with and into the Successor Issuer and the assumption by the Successor Issuer of all of the obligations of the Predecessor Issuer under the Indenture and the Notes, the Predecessor Issuer is automatically deemed released and discharged from its obligations under the Indenture and the Notes;

WHEREAS, pursuant to Section 5.01(a)(i) of the Indenture, the Successor Issuer may be a corporation, partnership (including a limited partnership), trust or limited liability

company organized or existing under the laws of the United States, any state or commonwealth thereof, the District of Columbia or any territory thereof;

WHEREAS, pursuant to Section 9.01(c), of the Indenture may be amended without the consent of any Holder to comply with Section 5.01 thereof;

New Guarantors

WHEREAS, pursuant to 9.01(j) of the Indenture, the Indenture may be amended without the consent of any Holder to add a Guarantor under the Indenture or to secure the Obligations thereunder; and

General

WHEREAS, pursuant to Sections 9.01(c), 9.01(d), 9.01(j) and 9.05 of the Indenture, the Trustee is authorized to execute and deliver this Supplemental Indenture.

NOW THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Issuers, the Existing Guarantors, the New Parent, the New Guaranteeing Subsidiaries and the Trustee mutually covenant and agree for the equal and ratable benefit of the Holders of the Notes as follows:

SECTION 1.  Capitalized terms used herein and not otherwise defined herein are used as defined in the Indenture.

SECTION 2. (a) Successor Issuer. The Successor Issuer hereby expressly assumes and agrees to perform all of the obligations of the Predecessor Issuer under the Indenture and the Notes.

(b)  Pursuant to Section 5.01 of the Indenture, the Predecessor Issuer is hereby automatically released and discharged from its obligations under the Indenture and the Notes;

(c)  The Successor Issuer, as Successor Company, hereby succeeds to, and is substituted for (so that from and after the date hereof, the provisions of the Indenture referring to the Predecessor Issuer (referred to as the “Company” in the Indenture) shall refer instead to the Successor Issuer), and may exercise every right and power of the Predecessor Issuer under the Indenture.

SECTION 3. New Parent Guarantee. The New Parent, by its execution of this Supplemental Indenture, agrees to be a Guarantor under the Indenture and to be bound by the terms of the Indenture applicable to a Guarantor that is not a Subsidiary Guarantor, including, but not limited to, Article 10 thereof.

SECTION 4. New Guaranteeing Subsidiaries. Each New Guaranteeing Subsidiary, by its execution of this Supplemental Indenture, agrees to be a Subsidiary Guarantor (as such term is defined in the Indenture) under the Indenture and to be bound by the terms of the Indenture applicable to the Subsidiary Guarantors, including, but not limited to, Article 10 thereof.

SECTION 5. Governing Law. This Supplemental Indenture shall be governed by and construed in accordance with the laws of the State of New York.

SECTION 6. Limitation on Liability. No past, present or future stockholder, officer, director, employee or incorporator of the New Parent or any New Guaranteeing Subsidiary shall have any liability under the Guarantee provided by such party, the Indenture or this Supplemental Indenture by reason of such person’s status as stockholder, officer, director, employee or incorporator.

SECTION 7. Ratification of Indenture; Supplemental Indentures Part of Indenture.  Except as expressly amended hereby, the Indenture (as supplemented and amended by this Supplemental Indenture) is in all respects ratified and confirmed and all the terms, conditions and provisions thereof shall remain in full force and effect.  This Supplemental Indenture shall form a part of the Indenture for all purposes, and every Holder of Notes heretofore or hereafter authenticated and delivered shall be bound hereby.

SECTION 8. Counterparts.  The parties may sign any number of copies of this Supplemental Indenture.  Each signed copy shall be an original, but all of them together represent the same agreement.  The exchange of copies of this Supplemental Indenture and of signature pages by facsimile, electronic or PDF transmission shall constitute effective execution and delivery of this Supplemental Indenture as to the parties hereto and may be used in lieu of the original Supplemental Indenture and signature pages for all purposes.

SECTION 9. Interpretation; Effect of Headings. This Supplemental Indenture is an amendment supplemental to the Indenture and the Indenture and this Supplemental Indenture will henceforth be read together. The Section headings herein are for convenience only and shall not affect the construction thereof.

SECTION 10. Conflicts and Inconsistencies. If there is any conflict or inconsistency between the Indenture and this Supplemental Indenture, the provisions of this Supplemental Indenture shall control.

SECTION 11. Obligations of the Trustee. Except as otherwise expressly provided herein, no duties, responsibilities or liabilities are assumed, or shall be construed to be assumed, by the Trustee by reason of this Supplemental Indenture. This Supplemental Indenture is executed and accepted by the Trustee subject to all the terms and conditions set forth in the Indenture with the same force and effect as if those terms and conditions were repeated at length herein and made applicable to the Trustee with respect hereto. The Trustee shall not be responsible for and makes no representation as to the validity or adequacy of this Supplemental Indenture, and it shall not be responsible for any statement or recital herein.

SECTION 12. Severability. If any provision of this Supplemental Indenture shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions hereof shall not in any way be affected or impaired thereby, and no Holder of any series of Notes shall have any claim therefor against any party hereto.

[Signature Pages Follow]

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