423 Area Code – Location Map, Time Zone & Lookup

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📞 423 Area Code — Quick Reference
📍 LocationChattanooga, Tennessee
🕐 Time ZoneCentral (UTC-6/UTC-5)
🗓️ StatusActive — Geographic

Got a call from 423? That number originates in Chattanooga, Tennessee. Whether you received an unexpected call from this number or you’re trying to figure out where a 423 number is based, this guide covers the exact location, time zone, spam reputation, blocking instructions, and which cities fall under this code.

📍 Where Is the 423 Area Code Located?

The 423 area code is located in Tennessee, primarily serving Chattanooga and the surrounding region. It’s a standard geographic area code under the North American Numbering Plan (NANP). Keep in mind that mobile number portability means someone could carry a 423 number with them after moving — so the code tells you where the number was issued, not necessarily where the person is right now.

423 Area Code — Location Details
State/ProvinceTennessee (TN)
Major CityChattanooga
CountryUnited States (+1)
Time ZoneCentral (UTC-6/UTC-5)
TypeGeographic — Standard
NANPA StatusActive

🕐 423 Area Code Time Zone

The 423 area code operates in the Central Time Zone (UTC-6/UTC-5). Here’s how it compares to other US time zones:

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 Business hours (good to call)     Early / late hours     Night — do not call
Official Resources: Report Fraud — FTC Do Not Call Registry NANPA Directory
Time ZoneDifference from 423
Eastern Time+1 hour
Central TimeSame time
Mountain Time-1 hour
Pacific Time-2 hours
💡 Calling Tip: Reach someone in the 423 area between 10 AM – 4 PM their local time for the best chance of an answer. Calls outside those hours are more likely to be screened or ignored.

🛡️ Is 423 Area Code Spam or Scam?

Seeing 423 on your caller ID doesn’t automatically mean spam — it’s a real area code used by many in Chattanooga. But robocallers frequently disguise their actual numbers behind familiar area codes like 423. If a 423 call feels off, hang up and verify independently.

⚠️ Red Flag: If a 423 caller demands immediate payment via gift cards, wire transfer, or crypto — hang up. No legitimate organization uses these methods. Verify by calling the company’s official number directly.

How to verify: Don’t call back the number — look up the official number for whatever organization the caller claimed to represent and call that instead. Google the full 10-digit number in quotes to check if others have reported it as spam.

📵 How to Block 423 Spam Calls & Texts

Block on iPhone

  1. Open Phone → tap Recents
  2. Tap ⓘ next to the 423 spam number
  3. Scroll down → “Block this Caller”
  4. Silence all unknowns: Settings → Phone → Silence Unknown Callers → ON

Block on Android

  1. Open Phone → find the 423 number
  2. Tap ⋮ menu → “Block number”
  3. For broader blocking: Settings → Blocked numbers → Unknown toggle ON

Report Spam

  1. Forward spam texts to 7726 (SPAM)
  2. Report at reportfraud.ftc.gov
  3. Register at donotcall.gov or call 1-888-382-1222

🔍 Who Called from 423? Reverse Lookup

  1. Google the full 10-digit number in quotes — catches ~70% of unknown callers
  2. Check Whitepages.com or Truecaller.com
  3. Search 800notes.com for community reports
  4. No voicemail left? Almost certainly spam — legitimate callers leave messages
⚠️ One-Ring Scam: If a 423 number rings once and hangs up, do NOT call back. This scam connects you to a premium-rate line that charges your bill.

🔗 Nearby Area Codes

CodeLocationTime Zone
615Nashville, TennesseeCentral
901Memphis, TennesseeCentral
931Clarksville, TennesseeCentral
865Knoxville, TennesseeCentral
731Jackson, TennesseeCentral

❓ 423 Area Code — FAQ

What state is 423 area code in?
The 423 area code is in Tennessee, serving Chattanooga and surrounding areas.
What city does 423 cover?
423 primarily covers Chattanooga and nearby communities in Tennessee.
Is 423 toll-free?
No. 423 is a geographic area code. Toll-free codes are 800, 833, 844, 855, 866, 877, 888.
What time zone is 423?
Central (UTC-6/UTC-5).
Is 423 a scam?
423 is legitimate — it serves real people in Chattanooga. But scammers may spoof 423 numbers. Verify suspicious callers independently.
Why do I keep getting 423 calls?
Repeated 423 calls without a known contact are likely robocalls. Use your phone’s Silence Unknown Callers feature.
Can I get a 423 number remotely?
Yes — VoIP services like Google Voice offer 423 numbers regardless of where you live.
Is 423 cell or landline?
423 covers both. US area codes don’t distinguish between mobile and landline.
How do I block 423 calls?
iPhone: Settings → Phone → Silence Unknown Callers. Android: Phone → Settings → Blocked numbers. For area-code blocking, use Truecaller or RoboKiller.

🔗 Related Area Code Guides

Updated April 2026 · Data from NANPA & FCC · areacodess.org/