Exhibit 3.439

State of Delaware

Secretary of State

Division of Corporations

Delivered 12:36 PM 10/11/2013

FILED 12:36 PM 10/11/2013

SRV 131188711 – 5414460 FILE

CERTIFICATE OF FORMATION

OF

TIME WARNER CABLE INTERNET HOLDINGS III LLC

This Certificate of Formation of Time Warner Cable Internet Holdings III LLC (the “Company”) is being executed by the undersigned for the purpose of forming a limited liability company pursuant to the Delaware Limited Liability Company Act.

1. The name of the Company is Time Warner Cable Internet Holdings III LLC.

2. The address of the registered office of the Company in the State of Delaware is Corporation Trust Center, 1209 Orange Street, Wilmington, DE 19801. The name of the Company’s registered agent at such address is The Corporation Trust Company.

3. This Certificate of Formation shall be effective upon filing.

IN WITNESS WHEREOF, the undersigned, an authorized person of the Company, has executed this Certificate of Formation this 11th day of October, 2013.

/s/ William C. Wesselman

William C. Wesselman,

Authorized Person