New Area Code 729 to Join 423 Region

CHATTANOOGA, Tenn. (WDEF) — A new area code 729 will soon be added to the existing 423 region, which covers cities like Bristol, Chattanooga, Johnson City, and Kingsport and others. Here’s what you need to know.

Starting August 5th a six-month permissive dialing period will begin to give customers enough time to adjust to making local calls digits.

“All calls in the 423-area code that are currently dialed with 7 digits need to be dialed using the area code plus the 7-digit number coming soon, but as of now your phone number going forward will not change the only people with the change will be people getting a new phone number to begin with” said Grace Marek with the Tennessee Public Utility Commission.  

Starting February 5th, 2025, all local calls within the 423-area code will require 10-digit dialing to be a complete call.

“Calls will have to be dialed using 10 digits for the call to be completed if they don’t include the area code, they will be routed to an announcement saying that their call cannot be completed as dialed. Beginning March 5th 1 month later that is actually going to be the time the area codes could possibly become available,” said Marek.