Mandatory 10-digit dialing coming to the 423 August 5

From Local 3 News: Some changes are coming to the way you call local numbers.

Beginning August 5, 2025, you must dial 10 digits (area code + 7-digit telephone number) on all local calls, including calls within your same area code. On and after this date, if you dial just 7 digits your call will not be completed, and a recording will instruct you to hang up and dial again, including the area code.

Then, starting September 5, 2025, new telephone lines or services may be assigned numbers with the new 729 area code. If you have a number in the new 729 area code, you must dial 10 digits or the call will not complete.

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 no later than August 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.

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.

The process is known as an area code overlay.

"It'll take some getting ready," said John Hutton with the Tennessee Public Utility Commission.

A six-month extension earlier in the year pushed the previously reported dates backward.