Area Code 423

Chattanooga, Tennessee · EST/EDT (UTC-5) · United States

Area Code
423
City
Chattanooga, TN
Time Zone
EST/EDT
UTC Offset
UTC-5 / UTC-4 DST
DST
Observed
Introduced
1995

Where Is Area Code 423?

Chattanooga, Johnson City, Kingsport — eastern Tennessee

Scenic City. First city in US to offer city-wide gigabit internet.

Major Cities & Neighborhoods
ChattanoogaJohnson CityKingsportBristol

Time Zone for Area Code 423

Standard Time
EST (UTC-5)
Daylight Time
EDT (UTC-4)
DST 2026 Start
March 8, 2026
DST 2026 End
November 1, 2026
Country
United States
IANA Zone
America/New_York

Calling Area Code 423

Domestic Calls

Dial 1 + 423 + 7-digit number for calls from outside the area. Local calls within the same area code may use 7-digit dialing where available.

International Calls

From outside United States: dial your country's exit code + 1 + 423 + number. From most countries, the format is +1-423-XXX-XXXX.

Best Time to Call

Area code 423 is in EST/EDT (UTC-5). Business hours are typically 9:00 AM – 5:00 PM local time. Remember that clocks shift during DST (March–November).

Scam Awareness

While (423) is a legitimate area code, scammers can spoof any number. Never share personal info with unknown callers. Verify by calling the organization directly.

Frequently Asked Questions

Other Tennessee Area Codes

More EST/EDT Area Codes

Area code data sourced from NANPA. Timezone data from IANA Time Zone Database. Last updated March 2026.