New 729 area code coming to East Tenn.

A new area code, 729, will soon join the existing 423 area code serving most of East Tennessee.

State regulators last week approved the creation of the new area code in the growing region since the number of available phone numbers in the existing 423 area code is expected to be exhausted within the next two years.

The 729 area code will have the same boundaries as the existing 423 zone, which covers a sprawling area across the Chattanooga region and most of the rest of East Tennessee, except the Knoxville region.

Knoxville, which was originally assigned 423 when East Tennessee was split from the 615 area code in 1995, is now in its own 865 area code.

Rather than split the 423 area code again and require existing customers to take on new numbers, the Tennessee Public Service Commission last week voted to add a new area code to the same region and give new phone users the 729 area code prefix, starting in the summer of 2024.

“The overlay is the least disruptive because it doesn’t require people to give up their existing number,” Timothy Schwarz, director of external affairs for the Tennessee Public Utility Commission, said in a telephone interview Monday. “It seems to be the preferred way to add more phone users.”

Existing phone users will keep their phone numbers but will have to dial 10 digits — the area code plus the seven-digit phone number — starting in mid-2024 under the plan adopted by the Tennessee Public Service Commission last week.

“Most people don’t have any problem dialing 10 digits any longer because they have cellphones with key numbers already programmed into the phone that dial automatically,” John Hutton, a telecommunications and utilities consultant for the Public Utilities Commission, said in an interview. “After a 13-month implementation period, someone who lives in the region that now has a 423 area code could

begin to receive a 729 area code number when they get new phone service or add more exchanges.”

The new area code will be the first such addition in Tennessee since Nashville added the 629 area code overlaying the 615 zone a decade ago, Hutton said. The 423 and new 729 area codes will cover 23 counties in East Tennessee and leave the 901 area code in West Tennessee as the only area code without a second overlapping area code, at least for the next few years.

Over the past decade, there have been 93 new overlay area codes across the United States, Canada and Mexico, according to the North American Numbering Plan Administrator, which administers telephone numbers and area codes. The administrator projects the 423 area code will run out of new numbers by the third quarter of 2025.

Splitting area codes is becoming less common than in the past, and a majority of the United States has moved to 10-digit numbers, according to the administrator.

To help gain public acceptance of the split in the 423 area code nearly three decades ago, Knoxville phone users were given the prefix 865, which spells out “VOL” in deference to the University of Tennessee Volunteers, or Vols.

AT&T originally developed the North American Numbering Plan in 1947 to simplify and facilitate direct dialing of long-distance calls. Hutton said the additional area codes have been needed across the country both to accommodate the growth in the number of phone lines and to reserve some numbers nationwide for standardized emergency calls, including 911 for fire, police and ambulance calls and 988 for suicide hotline calls, Hutton said.

Hutton said telecommunications providers will contact customers about the planned future changes.

“All the providers will handle notification,” he said.