Where is area code 423?
NANPA assigns 423 to Tennessee. The source report does not provide city-level coverage for this record, so this page does not guess a particular city. Browse other codes in Tennessee
Verified area-code information
423 Area Code
423 is an in-service United States area code assigned to Tennessee. It identifies a numbering region, not a caller’s current location.
Official Numbering RegionVerified NANPA Assignment
TennesseeArea Code 423
Country: United States•Time Zone: Eastern and Central•Overlays: 729•In Service: 11-Sep-1995
- Numbering country
- United States
- Area-code type
- Geographic
- Numbering region
- Tennessee
- Time-zone information
- Eastern and Central
- In service since
- 11-Sep-1995
View the official area-code maps ↗. Maps show numbering areas, not a caller’s location.
Time zones associated with 423
NANPA lists Eastern and Central for this numbering area. These are numbering-region time zones, not a caller’s current location.
Eastern time
Central time
An area code can span more than one time zone. Local daylight-saving rules may differ.
What area codes overlay 423?
The NANPA source lists 729 in the same overlay complex. An overlay can serve the same broad numbering area; individual numbers still do not prove where a person is.
How do you dial a 423 number?
Use the North American country calling code +1 followed by the three-digit area code and seven-digit local number. For example, write the pattern as +1 423 XXX XXXX. Local dialing rules and charges depend on your location and provider. Check a supported dialing format or check NANPA’s 10-digit dialing list.
Assigned prefixes in 423
NANPA’s US report listed 759 assigned prefixes on 2026-09-29. These are code assignments, not a count of active phone numbers or proof of a caller’s current carrier. Search any US area code and prefix.
Top rate-center labels by assigned prefixes
| Rate center | Assigned prefixes |
|---|---|
| CHATTNOOGA | 183 |
| JOHNSON CY | 67 |
| BRISTOL | 36 |
| CLEVELAND | 32 |
| KINGSPORT | 31 |
Top listed companies by assigned prefixes
| Assignment company | Assigned prefixes |
|---|---|
| BELLSOUTH TELECOMM INC DBA SOUTH CENTRAL BELL TEL | 119 |
| UNITED TELEPHONE-SOUTHEAST-TN DBA CENTURYLINK - TN | 83 |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TN | 79 |
| NEW CINGULAR WIRELESS PCS, LLC - GA | 77 |
| ONVOY, LLC - TN | 54 |
423 prefix lookup
759 assigned prefixes are listed for this area code. Search NANPA’s US central-office code assignments. The listed company and rate center describe an assignment; number portability means they cannot identify the current carrier, subscriber, or caller.
The area-code file loads when you search. The three-digit prefix stays in your browser.
Check a number with area code 423
Enter the full ten-digit number to see its structure and formatting. The check stays in your browser.
Check a 423 number
Enter a 10-digit +1 North American number. We check its structure and area-code record, not the caller’s identity or whether the line is active.
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Received an unfamiliar call?
The displayed number may be spoofed. Do not rely on an area code as proof of caller identity. If the caller claims to represent a business, end the call and contact that business using a number you found independently.
Common questions about 423
What time zone is area code 423 in?
423 is assigned to Tennessee, and the NANPA record associates it with Eastern and Central time. A phone number does not reveal its owner’s current time zone. The clock above uses a representative time zone for the numbering area.
Does 423 mean the caller is in Tennessee?
No. An area code is an assignment, and a person can travel, move, use internet calling, or display a spoofed number.
Can this page identify who called?
No. OfficialAreaCode has no live subscriber directory or spam-report database.