Chattanooga, July 30, 2025
News Summary
Beginning August 5, Chattanooga residents will be required to use 10-digit dialing, including the new 729 area code for all local calls. This change aims to meet the growing demand for available phone numbers, as the existing 423 area code is projected to run out by the end of 2025. Both area codes will function simultaneously, and the update will affect various devices and systems, prompting residents and businesses to reprogram their contact lists and materials accordingly.
Chattanooga Implementing 10-Digit Dialing with New 729 Area Code Starting August 5
Starting on August 5, residents in Chattanooga and the surrounding areas of the 423 area code will be required to use 10-digit dialing for all local calls. This change will affect all callers within the region, who will now need to include the area code when dialing numbers in their area code.
The move comes as part of the introduction of a new area code, 729, approved by the Tennessee Public Utility Commission. The implementation is designed to address the growing demand for phone numbers in the region, which includes Chattanooga, Bristol, Kingsport, Johnson City, and other nearby communities in eastern Tennessee.
Existing phone numbers will remain unchanged, but users who dial only the seven-digit number after August 5 will not be able to connect their calls. Instead, they will receive a message instructing them to redial using the new 10-digit format. New phone numbers assigned in the region will start utilizing the 729 area code from September 5.
Both 423 and 729 area codes will operate simultaneously, meaning that all users must switch to using the 10-digit dialing format for local calls. Long-distance calls will continue to require the 1 + area code + number dialing format, and emergency numbers like 911, 988, 211, and 411 will still be dialed using the usual three-digit format.
Impact on Residents and Businesses
As residents adjust to this change, it is crucial for them to reprogram their contact lists, security systems, fax machines, and medical alert devices to ensure they include the area code in all phone numbers. Additionally, businesses and individuals are advised to update all communication materials, including websites and records, to reflect the full 10-digit phone number.
This initiative aims to accommodate a projected shortfall of available numbers in the 423 area code, which is expected to run out by the end of 2025. The introduction of the 729 area code is anticipated to expand the region’s number capacity for approximately 34 years. The original rollout for these changes was delayed due to infrastructure damages caused by Hurricane Helene.
Background Context
The 423 area code was established in 1995 after splitting from the 615 area code. Since then, it has faced challenges in number availability due to the growth of the region. The decision to introduce the 729 area code as an overlay allows for more efficient use of numbering resources while maintaining service continuity for current users in the area.
Residents and businesses are encouraged to reach out to their service providers or device manufacturers for any questions regarding the necessary updates related to the new dialing requirements.
Important Changes Summary
| Change | Details |
|---|---|
| 10-Digit Dialing Requirement | Mandatory for all local calls in the 423 area code starting Aug 5 |
| New Area Code | 729 area code introduced to meet demand starting Sep 5 |
| Current Numbers | All existing 423 numbers remain unchanged |
| Long-Distance Calls | 1 + area code + number format still applies |
| Emergency Numbers | Dial as usual without 10-digit format |
FAQs
What is the new dialing requirement in Chattanooga?
Starting August 5, all local calls within the 423 area code will require 10-digit dialing, including the area code.
When will the new area code 729 be implemented?
The new area code 729 will be in use for new numbers starting September 5.
Will my current number change with the new area code?
No, current numbers in the 423 area code will remain unchanged.
What happens if I only dial seven digits after August 5?
You will not be able to complete your call and will receive a message prompting you to redial using the 10-digit format.
Do I need to update my devices for the new dialing requirements?
Residents are advised to reprogram contact lists, fax machines, security systems, and medical alert devices to accommodate the new dialing format.
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Author: STAFF HERE CHATTANOOGA WRITER
The CHATTANOOGA STAFF WRITER represents the experienced team at HEREChattanooga.com, your go-to source for actionable local news and information in Chattanooga, Hamilton County, and beyond. Specializing in "news you can use," we cover essential topics like product reviews for personal and business needs, local business directories, politics, real estate trends, neighborhood insights, and state news affecting the area—with deep expertise drawn from years of dedicated reporting and strong community input, including local press releases and business updates. We deliver top reporting on high-value events such as Riverbend Festival, Chattanooga Oktoberfest, and Moon River Festival. Our coverage extends to key organizations like the Chattanooga Area Chamber of Commerce and United Way of Greater Chattanooga, plus leading businesses in manufacturing, insurance, and utilities that power the local economy such as Volkswagen Chattanooga, BlueCross BlueShield of Tennessee, and EPB. As part of the broader HERE network, including HEREBristol.com, HEREKnoxville.com, HEREMemphis.com, and HERENashville.com, we provide comprehensive, credible insights into Tennessee's dynamic landscape.
