423 Area Code
Covers Chattanooga and nearby communities in Tennessee.
(423) 555-0142Area code 423 map
Interactive coverage map for area code 423, centered on Chattanooga, Tennessee
36.3134, -82.3535
Open in OpenStreetMapArea code 423 coverage map — centered on Chattanooga. Shaded area shows the approximate reach around the primary city.
Area code 423 is a telephone area code in Tennessee, anchored on Chattanooga. It reaches roughly 291,000 people across places such as Chattanooga, Johnson City, Kingsport, Bristol and more. The region observes Eastern time, so a number like (423) 555-0142 is on that clock right now. On the ground it spans Hamilton, Washington, Sullivan and nearby counties. It is not currently paired with an overlay code. Local calls inside the 423 area can generally be placed with ten digits, and you do not need a leading 1 for domestic calls. On this page you'll find a live local clock for Chattanooga, an interactive coverage map, the cities and counties 423 serves, its overlay and neighboring codes, and tips on spotting 423 spam calls.
Cities covered by 423
Cities & neighborhoods
- Chattanooga
- Johnson City
- Kingsport
- Bristol
- East Chattanooga
- East Ridge
- Morristown
- South Cleveland
Counties
- Hamilton
- Washington
- Sullivan
- Hamblen
Looking for the broader picture? See all Tennessee area codes.
Nearby & overlay area codes
Overlay codes (same area)
These share 423’s geography — a number in either code can be on the same street.
423 has no overlay code right now.
Neighboring codes
Codes for adjacent regions and metros.
Is a call from 423 a scam?
Area code 423 serves Chattanooga and the surrounding area, so most calls are ordinary local and business traffic. As everywhere, spam and robocalls do use 423 numbers, frequently by spoofing a local-looking caller ID to boost pickup rates. The area code itself tells you nothing about who is really calling, so judge the call by what's said, not the number.
Red flags to watch for
- Pressure to act right now, or threats of arrest, fines, or service being cut off.
- Requests to pay with gift cards, wire transfer, crypto, or a payment app.
- Asking for passwords, one-time codes, your SSN, or full card/bank numbers.
- A robocall or recording, or a number that won’t let you call back.
When unsure, hang up and call the organization back on a number you look up yourself.
Calling a 423 number from abroad
Every 423 number is a US/Canada +1 number. From a mobile anywhere, the simplest approach is to dial it in international format:
+1 423 555-0142If your phone can’t dial the +, replace it with your country’s exit code, then 1, then the number:
- UK, Germany, France & most of Europe
00 1 423 555-0142 - Australia
0011 1 423 555-0142 - Japan
010 1 423 555-0142 - Mexico
00 1 423 555-0142
Within the US and Canada you don’t need any of this — just dial the ten digits 423 555-0142.
Reverse phone lookup
Check any US or Canada number to see whether it's a working line, which carrier it sits on, whether it's mobile, landline or VoIP, and roughly where it's registered.
Shows carrier, line type and location. Owner name isn't available here.
Results are for personal, informational use only and may not be used for employment, credit, housing or tenant-screening decisions.
Area code 423: frequently asked questions
Where is the 423 area code located?
The 423 area code is located in Tennessee, centered on Chattanooga. It covers Hamilton, Washington, Sullivan, Hamblen and nearby communities including Chattanooga, Johnson City, Kingsport, Bristol, East Chattanooga, East Ridge.
What time zone is 423 in?
Area code 423 is in the Eastern time zone (UTC-5 (EST) / UTC-4 (EDT)). You can see the exact current local time for Chattanooga on the live clock above.
What cities use area code 423?
Cities and areas that use 423 include Chattanooga, Johnson City, Kingsport, Bristol, East Chattanooga, East Ridge. Its primary city is Chattanooga, TN.
Do I need to dial 1 before 423?
You generally do not need to dial a leading 1 for domestic calls to 423. Ten-digit dialing (the 423 code plus the seven-digit number) is the safest habit.
Is 423 a toll-free or scam number?
No — 423 is a normal geographic area code for Chattanooga, not a toll-free code (toll-free codes are 800, 833, 844, 855, 866, 877 and 888). A 423 number is not inherently a scam, but the code can be spoofed. See the spam-call section above for how to tell.
What are the overlay area codes for 423?
Area code 423 does not currently have an overlay code; it is not layered on top of another code in the same area.