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AREA CODE · TENNESSEE

Area code 423

Area code 423 covers Chattanooga, Tennessee. Map, time zone, overlays, carriers, the full list of prefixes and how to dial it.

State: Tennessee Major City: Chattanooga Eastern Time (ET) Overlay: 423/729
01 / WHERE IT IS

Where is area code 423?

Area code 423 is assigned to Chattanooga and the surrounding region in Tennessee. Calls to numbers that start with 423 are routed to this area.

Area code 423 shares its territory with 729. Because it is an overlay, local calls require dialing all 10 digits.

Counties covered

Hamilton CountySullivan CountyWashington CountyBradley CountyMcMinn CountyHawkins CountyHamblen CountyMonroe CountyGreene CountyCarter CountyCampbell County

Line types

  • Mobile 32.59%
  • Landline 67.41%
02 / MAP

Area code 423 on the map

The shaded area joins the code’s numbering centers; the marker shows its main city.

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© OpenStreetMap contributors

03 / LOCAL TIME

Current time in Chattanooga

This area code is in the Eastern Time (ET) time zone.

Local timeChattanooga, TN--:--:--

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America/New_YorkLive
04 / HOW TO DIAL

How to call Chattanooga

WITHIN THE US423 XXX XXXX

Always 10 digits — landline, mobile or VoIP. Local, long distance or a different state: the format is always the same. You do not need to dial the 1 first.

FROM ABROAD+1 423 XXX XXXX

Exit codes: 00 Europe/Mexico · 011 Canada · 010 Japan · + universal

WHATSAPP / IMESSAGE+1 423 XXX XXXX

Always save the number in international format so messaging apps recognize it correctly:

Call typeTraditional landlineMobile / VoIP
Local (same area code)10 digits10 digits
US long distance1 + 10 digits10 digits
Emergency911911
🌐Universal+1 423 555 0123
🇪🇸🇲🇽Spain / Mexico00 1 423 555 0123
🇦🇺Australia0011 1 423 555 0123
🇯🇵Japan010 1 423 555 0123
HAVE THE FULL NUMBER?

Learn more about that number.

Check the line type and the carrier the number block was originally assigned to.

10 digits to see the carrier and line type of the number

05 / CARRIERS

Carriers in area code 423

Share of the number blocks by carrier and line type.

Landline

AT&T
26%
Lumen Technologies
24%
Sinch
10%
Windstream Communications
6%
Bandwidth
6%
Others
27%

Mobile

Verizon Wireless
32%
AT&T Mobility
31%
T-Mobile USA
26%
UScellular
5%
USA Mobility
3%
Others
4%

Carrier shown is the original assignment of each number block and may differ today because of number portability.

06 / PREFIXES

Complete list of prefixes for area code 423

758 number blocks (NXX) assigned in this area code.

PrefixTypeCityCarrier
(423) 200 Landline Morristown Lumen TechnologiesLEVEL 3 COMMUNICATIONS, LLC - TN
(423) 201 Landline La Follette Lumen TechnologiesLEVEL 3 COMMUNICATIONS, LLC - TN
(423) 202 Landline Johnson City Verizon BusinessMCIMETRO ACCESS TRANSMISSION SERVICES LLC - TN
(423) 203 Mobile Chattanooga Boost MobileBOOST SUBSCRIBERCO L.L.C.
(423) 205 Landline Etowah SinchONVOY, LLC - TN
(423) 206 Landline Chattanooga RingCentralRCLEC, INC.
(423) 207 Landline Midway (Washington) Lumen TechnologiesLEVEL 3 COMMUNICATIONS, LLC - TN
(423) 208 Mobile Chattanooga AT&T MobilityNEW CINGULAR WIRELESS PCS, LLC - GA
(423) 209 Landline Chattanooga AT&TBELLSOUTH TELECOMM INC DBA SOUTH CENTRAL BELL TEL
(423) 210 Mobile Tellico Plains UScellularUNITED STATES CELLULAR - TN

Showing 10 of 758 prefixes

07 / FAQ

Frequently asked questions about area code 423

Where is area code 423 used?
Area code 423 serves Chattanooga and the surrounding area in Tennessee, including Hamilton County, Sullivan County, Washington County, Bradley County, McMinn County.
What city is area code 423 from?
The main city of area code 423 is Chattanooga, TN.
What time zone is area code 423 in?
Area code 423 is in the Eastern Time (ET) time zone (America/New_York).
Is 423 an overlay area code?
Yes. It shares its territory with 729. In an overlay, every call requires dialing all 10 digits.
How do I call a number with area code 423 from the United States?
Dial the 10 digits: 423 + 7-digit number. For some long-distance calls from a landline you may need to add a 1 first.
How do I call a 423 number from another country?
Dial your country's exit code (or +), then 1, then 423 and the seven-digit number. From a mobile you can use +1 423 XXX XXXX.
Which carriers use area code 423?
Most landline blocks belong to AT&T and most mobile blocks to Verizon Wireless. The carrier shown is the original assignment and may differ today because of number portability.
Is area code 423 for landlines, mobiles or both?
Both. About 67.41% of the number blocks are landline, 32.59% mobile.
How do I save a 423 number in WhatsApp or my phone?
Save it in international format: +1 423 XXX XXXX. That way WhatsApp, iMessage and Telegram recognize it from any country.
Is it safe to answer calls from area code 423?
The area code only shows the region a number was assigned to; it does not tell you who is calling. Scammers can fake any area code, so do not share personal or banking information with unknown callers, and let unknown numbers go to voicemail.
KEEP EXPLORING

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