North American Numbers Source-cited · ownership disclosed
Area code
729
In service
United States · since 2025

Chattanooga / Tri-Cities (overlay)

All-services overlay of area code 423 across East Tennessee, in service since September 2025. Re-check NANPA for latest status.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Chattanooga / Tri-Cities (overlay)
Type
geographic
Status
in service
In service since
2025
Projected exhaust
2081 Q1

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 729 is

Same non-contiguous East Tennessee geography as 423 (Chattanooga/Cleveland south, Tri-Cities northeast)..

Communities served wholly or partly by 729:

ChattanoogaClevelandKingsportJohnson CityBristolMorristownGreeneville

Same geography as 423; 729 numbers distributed across the overlay.

B · Relationships

How it relates to other codes

The codes 729 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Overlay · 2025 423 Chattanooga / Tri-Cities Overlays 423 across identical (non-contiguous) geography.
What's changing. Overlay of 423; in service since Sept 2025. 2023+ code — re-check NANPA for current status.
C · History

How 729 got here

2023-05-30
Tennessee Public Utility Commission approved 729 as an all-services overlay of 423.
Source: Wikipedia
2024-08-05
Permissive ten-digit dialing began.
Source: Wikipedia
2025-09-05
Official in-service date for 729.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
14
Prefixes available
786

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 729 with another code →
Sources
Wikipedia ↗
Area codes 423 and 729
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.