New 729 area code approved for 423 region; 10-digit dialing required starting Aug. 5

Published 2:17 pm Tuesday, July 29, 2025

NASHVILLE — The Tennessee Public Utility Commission has approved the introduction of the new 729 area code to the existing 423 region to meet growing demand for new telephone numbers. The change affects communities such as Bristol, Chattanooga, Johnson City and Kingsport, as well as numerous smaller towns across two non-contiguous areas of eastern Tennessee.

The addition of the 729 area code will be implemented through an area code overlay, meaning existing numbers in the 423 area code will remain unchanged. However, beginning Aug. 5, 2025, all local calls within the 423 region must be dialed using 10 digits — the area code followed by the seven-digit number. Calls dialed with only seven digits will no longer be completed.

Starting Sept. 5, 2025, new telephone lines or services may be assigned numbers with the 729 area code. Both area codes will serve the same geographic region, and 10-digit dialing will be required for all customers regardless of which code they have.

Key points about the 423/729 overlay include:

• Current phone numbers will not change.

• All local calls must use 10-digit dialing.

• Long distance calls still require 1 + area code + number.

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• Local call status and rates will not change.

• Emergency and service short codes such as 911, 988 and 211 remain unchanged.

Customers are encouraged to update contact information and ensure that any equipment or services that rely on 7-digit dialing — including medical alert systems, fax machines and alarm systems — are reprogrammed to support 10-digit dialing. Reprogramming should be completed by Aug. 5 to avoid service disruptions.

For more information, visit the Tennessee Public Utility Commission at www.tn.gov/tpuc/news.html or contact your local service provider.