Area Code 423
Tennessee
Area code 423 serves Tennessee, primarily Chattanooga, in the Central Time (CT) time zone. It has served the region since 11-Sep-1995.
Overlay Area Code
This area code is part of an overlay region, meaning the same geographic area is served by multiple area codes. Overlay codes were introduced to meet growing demand for phone numbers without requiring existing customers to change their numbers.
This area code shares its geographic region with: area code 729 (Chattanooga).
In service since: 11-Sep-1995
Area Code Splits
Parts of this area code’s original geographic region were later assigned new area codes through splits. When a split occurs, some customers in the original area code region are assigned the new area code.
Split into: area code 865 (Knoxville).
Demographics
The estimated population served by area code 423 is approximately 2,359,591. The population density is 115 people per square mile, which is higher than the national average of 94. The median household income is $57,408, which is lower than the national median of $78,538. Approximately 23.0% of adults hold a bachelor's degree or higher, compared to the national rate of 35.0%. This rate is lower than the national average. The poverty rate stands at 16.0%, which is higher than the national rate of 12.4%.
History
Area code 423 was established in 1995 as a geographic area code. Over time, area code area code 865 was split from 423. It shares its territory with area code area code 729.
Geographic Coverage
Area code 423 serves Tennessee, primarily the Chattanooga area, in the Central Time (CT). It covers 132 communities. The geographic center of this area code is approximately 35.81°N, 84.00°W.
Demographics & Economics
- Total Population
- 2,359,591
- Population Density
- 115 people/sq miabove U.S. average (U.S.: 94 people/sq mi)
- Median Household Income
- $57,408below U.S. median (U.S.: $78,538)
- Poverty Rate
- 16.0%above U.S. average (U.S.: 12.4%)
- Unemployment Rate
- 5.4%near U.S. average (U.S.: 5.2%)
- Education Attainment
- Bachelor's Degree+23.0%below U.S. average (U.S.: 35.0%)High School or Lower40.2%
Statistics are population-weighted aggregations from Census ACS 5-year estimates.See Sources for details.
Geographic Coverage
State
TN
Major Cities
- Chattanooga
- Johnson City
- Kingsport
- Cleveland
- Morristown
- Bristol
- East Ridge
- Greeneville
- Elizabethton
- Athens
- Soddy-Daisy
- Red Bank
- Middle Valley
- Collegedale
- Signal Mountain
- Bloomingdale
- Harrison
- South Cleveland
- La Follette
- Dayton
- Church Hill
- Newport
- Sweetwater
- Jonesborough
and 108 more cities
Time Zones
- Central Time (CT)
- Eastern Time (ET)
Current Time
This area code spans multiple time zones.
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 423).
| County | Population | Share |
|---|---|---|
| Hamilton, TN | 418,151 | 17.7% |
| Sullivan, TN | 217,891 | 9.2% |
| Washington, TN | 192,282 | 8.1% |
| Hawkins, TN | 126,241 | 5.4% |
| Carter, TN | 124,281 | 5.3% |
| Bradley, TN | 120,885 | 5.1% |
| McMinn, TN | 98,617 | 4.2% |
| Unicoi, TN | 94,681 | 4.0% |
| Bledsoe, TN | 90,392 | 3.8% |
| Greene, TN | 84,366 | 3.6% |
| Sequatchie, TN | 71,280 | 3.0% |
| Marion, TN | 68,947 | 2.9% |
| Cocke, TN | 67,202 | 2.8% |
| Hamblen, TN | 66,080 | 2.8% |
| Monroe, TN | 55,771 | 2.4% |
| Polk, TN | 55,266 | 2.3% |
| Campbell, TN | 47,180 | 2.0% |
| Rhea, TN | 40,179 | 1.7% |
| Jefferson, TN | 39,592 | 1.7% |
| Claiborne, TN | 38,906 | 1.6% |
| Scott, TN | 25,724 | 1.1% |
| Van Buren, TN | 24,160 | 1.0% |
| Meigs, TN | 23,801 | 1.0% |
| Loudon, TN | 22,760 | 1.0% |
| Roane, TN | 20,574 | 0.9% |
| Johnson, TN | 19,242 | 0.8% |
| Morgan, TN | 19,065 | 0.8% |
| Hancock, TN | 18,324 | 0.8% |
| Scott, VA | 14,491 | 0.6% |
| Cumberland, TN | 13,012 | 0.6% |
| Union, TN | 12,449 | 0.5% |
| Sevier, TN | 7,430 | 0.3% |
| Franklin, TN | 6,604 | 0.3% |
| Lee, VA | 6,160 | 0.3% |
| Grainger, TN | 4,156 | 0.2% |
| Fentress, TN | 2,313 | 0.1% |
| Anderson, TN | 1,136 | 0.0% |
Call Context
This area code covers multiple cities and communities across a broad region in Tennessee. The region spans Central and Eastern time zones.
Nearby Area Codes
Area codes geographically closest to 423.
Other Area Codes in Tennessee
Area codes that also serve Tennessee, linked for easy comparison.
Frequently Asked Questions
Common questions about area code 423 and how phone numbering works.
Phone numbers are assigned based on where the number was originally provisioned, not the caller's current location. Mobile phones retain their number when users move, and businesses may use numbers from regions where they don't have a physical presence. VoIP services can also provision numbers from virtually any area code.
Yes, mobile phones can have numbers from any area code in the region they were activated. Wireless carriers assign numbers from available pools regardless of phone type. When users change carriers or move to new areas, they typically keep their original number, which may have a different area code than their current location.
Start by looking up the area code on this site to understand its general geographic region. For the specific number, options include using your carrier's caller ID features or checking public directories. If you suspect fraud, you can report it to the FTC. To file a complaint about robocalls or spoofed numbers, visit the FCC Consumer Complaint Center. You can also register your number with the National Do Not Call Registry to reduce unwanted calls. Keep in mind that caller ID can display any name the caller chooses to set.
When an area's pool of available phone numbers runs low, regulators may introduce an "overlay" area code that covers the same geographic territory as the original. Both codes coexist, and new numbers are assigned from whichever code has availability. This area code shares its region with area code 729. Learn more in our overlay vs split guide.
While Cleveland is a prominent city in this area code's coverage, the code serves the broader surrounding region as well. Area codes are assigned geographically and typically cover multiple cities, towns, and communities beyond any single anchor city.
The estimated total population served by area code 423 is based on aggregated U.S. Census Bureau data for the counties within this area code. The population varies significantly between dense urban codes serving millions and rural codes covering smaller populations. You can find the specific population figure in the demographics section above.