The rapid population growth in East Tennessee has necessitated the introduction of a new area code, 729, to supplement the existing 423 area code. This change aims to address the impending exhaustion of available central office codes in the 423 region.
Grace Marek, Financial Regulatory Analyst with the Tennessee Public Utility Commission, stated, “The North American Numbering Plan administrator notified the Tennessee Public Utility Commission that the 423 number plan area is projected to exhaust its availability of central office codes.”
Implementation Timeline and Transition Plan
The new 729 area code overlay will be rolled out in various stages over the next few years. To help residents adjust, the state of Tennessee encourages dialing the area code along with the seven-digit phone number starting on August 5, 2024. This transition period aims to familiarize people with the new 10-digit dialing process.
“Starting in February 2025, all local calls made within the existing 423 area code region must be dialed using ten digits,” Marek explained. “On and after February 5, 2025, calls using just seven digits will not be completed and they’ll be routed to an announcement informing them that the call cannot be completed as dialed.”