Tri-Cities region prepares for 729 area code addition

GREENEVILLE, Tenn. (WJHL) – Population growth in East Tennessee has required the state to add an additional area code to the current 423 area code.

“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,” said Grace Marek, Financial Regulatory Analyst with the Tennessee Public Utility Commission.

A new 729 area code overlay will be implemented into the area in various stages over the next few years.

The State of Tennessee wants people to start dialing the area code and the 7 digit phone number they wish to call starting on Aug. 5, to get used to dialing 10 digits instead of 7.

“Starting in February 2025, all local calls made within the existing 423 area code region must be dialed using ten digits,” said Marek. “On and after February 5, 2025 calls using just seven digits will not be completed and they’ll be routed to an announcement kind of telling them that the call cannot be completed as dialed.”

Marek told News Channel 11 that if you already have a 423 area code, your number will not change, and when you dial a number with a different area code, it will still be known as a local call and you shouldn’t be charged with any long distance phone call fees.

“March 5 of 2025, new telephone lines or services may be assigning members with the new 729 area code,” said Marek. “The new 729 area code will coexist everywhere in the region where the 423 area code currently exists.”

After March 5, 2025, people will have to dial 10 digits using the 423 or the 729 area code.

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