New area code use begins for area famously known as the "423"

From Local 3 News: With new telephone numbers in high demand, in 2024, the Tennessee Public Utility Commission approved the addition of the new 729 area code to the existing 423 area code region, which covers two non-contiguous regions in eastern Tennessee, serving communities such as Bristol, Chattanooga, Johnson City and Kingsport, as well as many other smaller communities.

This process is known as an area code overlay.

"It'll take some getting ready," said John Hutton with the Tennessee Public Utility Commission.
 
In August 5, 2024, a six-month permissive dialing period began to give customers adequate time to adjust to including the area code when they make a local call. 
During this time, local calls could be made with either 7 or 10 digits.

But starting February 5, 2025, all local calls made within the 423 area code must be dialed using 10 digits (area code and the 7-digit telephone number).

On and after this date, calls using just 7 digits will not be completed, and will be routed to an announcement.

Then on March 5, 2025, new telephone lines or services may be assigned numbers from the new 729 area code. The new 729 area code will co-exist everywhere in this region with the 423-area code.

Anyone receiving a 729 number will be required to dial 10 digits as well.  

This change has business owners like Delisa Bridges concerned because she's afraid she will lose business.
 
"I think it's devastating, it's going to be confusing to the clients, to the newcomers, and anybody trying to find me," said Bridges.

The key facts to know about the upcoming 423/729 area code overlay are:

• Current telephone numbers, including current area code, will not change.
• Dial the area code + telephone number for all local calls, including calls within the same area code.
• Continue to dial 1 + area code + telephone number for long distance calls.
• What is a local call now will remain a local call.
• The price of a call, coverage area, or other rates and services will not change due to the overlay.
• You can still dial just three digits to reach 911 and 988, as well as 211, 311, 411, 511, 611, 711 and 811 where available.

To prepare for the new dialing procedure:

• Identify your telephone number as a 10-digit number and include the area code when giving the number to friends, family, business associates and customers, etc.
• Ensure all services, automatic dialing equipment, or other types of equipment that are programmed to dial a 7-digit number are reprogrammed to include the area code and to recognize the new 729 area code as a valid area code. Some examples include life-safety systems and medical monitoring devices, fire or burglar alarm and security systems or gates, cordless and mobile phone contact lists, fax machines, Internet dial-up numbers, ankle monitors, speed dialers, call forwarding settings, voicemail services, and other similar functions. Many systems operate on 10-digit dialing by default, but some older equipment may still use 7 digits.  Please contact your medical alert or security provider if you are not sure whether your equipment needs to be reprogrammed to accommodate the upcoming change to 10-digit local dialing. Any needed reprogramming of such alarm and home security equipment must be done between August 5, 2024, and February 5, 2025.
• Update websites, personal and business stationery and checks, advertising materials, personal and pet ID tags, and other such items to ensure the area code is included.