IEBtZWRpYSBvbmx5IHNjcmVlbiBhbmQgKG1heC13aWR0aDogNzgxcHgpIHsgICB9IEBtZWRpYSBvbmx5IHNjcmVlbiBhbmQgKG1heC13aWR0aDogNTk5cHgpIHsgICB9IA==
LnRiLWZpZWxke21hcmdpbi1ib3R0b206MC43NmVtfS50Yi1maWVsZC0tbGVmdHt0ZXh0LWFsaWduOmxlZnR9LnRiLWZpZWxkLS1jZW50ZXJ7dGV4dC1hbGlnbjpjZW50ZXJ9LnRiLWZpZWxkLS1yaWdodHt0ZXh0LWFsaWduOnJpZ2h0fS50Yi1maWVsZF9fc2t5cGVfcHJldmlld3twYWRkaW5nOjEwcHggMjBweDtib3JkZXItcmFkaXVzOjNweDtjb2xvcjojZmZmO2JhY2tncm91bmQ6IzAwYWZlZTtkaXNwbGF5OmlubGluZS1ibG9ja311bC5nbGlkZV9fc2xpZGVze21hcmdpbjowfQ==
Area Code Overview
Area code 423 is a geographic telephone area code in Tennessee that went into service on September 11, 1995. The geographic regions covered by this area code overlay has a population of approximately 1,476,733.
Overlay and Dialing Rules
- Area Code: 423
- State: Tennessee
- Type: General Purpose Code
- In Service Date: September 11, 1995
- Overlay Complex: 423/729
- Local Dialing Plan: This area does require you to dial the area code when calling locally.
Estimated Number of Assigned Phone Numbers in Area Code 423
This area code is ranked 116th out of 363 nationwide in estimated assigned phone numbers. Within the state territory it serves, it is ranked 2nd out of 7.
6,025,000
Estimated Service-Type Mix of Assigned Phone Numbers in Area Code 423
Wireless
2,315,000 assigned
38.42%
Wireline and VoIP
3,241,000 assigned
53.79%
Other / Unclassified
469,000 assigned
7.78%
Estimated Share of Wireless Numbers Originally Assigned to Each Carrier in Area Code 423
Estimated assigned wireless phone numbers: 2,315,000
Numbers may later be ported to another carrier, but this chart reflects original number assignment, not current subscriber share.
Verizon Wireless 1,028,000 (44.41%)
AT&T Wireless 687,000 (29.68%)
T-Mobile 433,000 (18.70%)
SUNCOM DBA T-MOBILE USA 116,000 (5.01%)
UScellular 49,000 (2.12%)
Optimum Mobile 2,000 (0.09%)
Estimated Share of Wireline and VoIP Numbers Originally Assigned to Each Carrier in Area Code 423
Estimated assigned wireline and VoIP phone numbers: 3,241,000
Bandwidth 388,000 (11.97%)
ELECTRIC POWER BOARD OF CHATTANOOGA 141,000 (4.35%)
Comcast Business 96,000 (2.96%)
CHARTER IP ENABLED SERVICES, LLC 92,000 (2.84%)
TERRA NOVA TELECOM INC. 42,000 (1.30%)
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN 40,000 (1.23%)
Other / Unclassified Assigned Numbering in Area Code 423
Estimated assigned other or unclassified phone numbers: 469,000
HIGHLAND TEL. COOP, INC. 100,000 (21.32%)
SPOK, INC. 70,000 (14.93%)
TELEPORT COMMUNICATIONS AMERICA, LLC - TN 66,000 (14.07%)
TELLICO TEL. CO., INC. 40,000 (8.53%)
BLEDSOE TEL. COOP. 30,000 (6.40%)
BRIGHTSPEED OF EASTERN TENNESSEE, LLC 30,000 (6.40%)
BRISTOL TENNESSEE ESSENTIAL SERVICES - TN 30,000 (6.40%)
TWIN LAKES COMMUNICATIONS, INC. - TN 15,000 (3.20%)
BRIGHTSPEED OF SOUTHERN TENNESSEE, LC 10,000 (2.13%)
ETC COMMUNICATIONS, L.L.C. - TN 10,000 (2.13%)
PRO PAGE PARTNERS, LLC 10,000 (2.13%)
SKYLINE TEL. MEMBERSHIP CORP. 10,000 (2.13%)
Cities and Towns in Area Code 423
Apison, Tennessee Athens, Tennessee Baileyton, Tennessee Ball Play, Tennessee Benton, Tennessee Blountville, Tennessee Bluff City, Tennessee Bristol, Tennessee Bulls Gap, Tennessee Butler, Tennessee Charleston, Tennessee Chattanooga, Tennessee Church Hill, Tennessee Cleveland, Tennessee Cokercreek, Tennessee Collegedale, Tennessee Copperhill, Tennessee Cumberland Gap, Tennessee Dayton, Tennessee Decatur, Tennessee Deer Lodge, Tennessee Dunlap, Tennessee Elizabethton, Tennessee Englewood, Tennessee Erwin, Tennessee Etowah, Tennessee Fall Branch, Tennessee Fork Ridge, Tennessee Georgetown, Tennessee Greeneville, Tennessee Hampton, Tennessee Huntsville, Tennessee Jasper, Tennessee Jellico, Tennessee Johnson City, Tennessee Jonesboro, Tennessee Kingsport, Tennessee La Follette, Tennessee Limestone, Tennessee Madisonville, Tennessee Midway, Tennessee Morristown, Tennessee Mosheim, Tennessee Mountain City, Tennessee New Tazewell, Tennessee Newport, Tennessee Ninemile, Tennessee Niota, Tennessee Oakdale, Tennessee Oneida, Tennessee Ooltewah, Tennessee Petros, Tennessee Pikeville, Tennessee Riceville, Tennessee Roan Mountain, Tennessee Robbins, Tennessee Rogersville, Tennessee Shady Valley, Tennessee Sneedville, Tennessee Soddy Daisy, Tennessee South Pittsburg, Tennessee Spring City, Tennessee Stone, Tennessee Sunbright, Tennessee Surgoinsville, Tennessee Sweetwater, Tennessee Tellico Plains, Tennessee Vonore, Tennessee Wartburg, Tennessee Whitwell, Tennessee These geographic regions are also served by area code 729.
How These Figures Were Built
These figures are estimates based on public phone-number assignment records. They are meant to show the likely mix of assigned phone numbers associated with area code 423, not live customer counts.
Some providers may have assigned phone numbers tied to this area code even if they do not actively market or sell service locally. These figures reflect public number-assignment records, not confirmed local service availability.
They also do not reflect number portability at the individual phone-number level, so some numbers may now be used on a different network or by a different provider than the original assignment records suggest.
Population data and locality matching provided by GeoNames.
Last refreshed: April 15, 2026 6:22 pm