Area code
Area code 423 — Chattanooga, TN
Tennessee · in service since September 11, 1995
Area code 423 covers parts of Tennessee; the place with the most of its prefixes is Chattanooga. It is an overlay: 729 serves the same area, so neighbors can have different area codes.
Overlay, same area: 729
Local time in Chattanooga
Spam reports from Sep 23 – Oct 22, 2026
High #19 of 461 codes
1,158 FTC complaints
Consumer reports, not verified by the FTC.
See the reports- Time zonesEastern Time, Central Time
- Local calls10 digits
- Prefixes779 assigned
- Runs out~1Q 2081
- Unwanted call?Block & report
Spam call reports about 423 numbers
Complaints by week
Sep 11 – Oct 22, 2026Show as table
| Week starting | Complaints |
|---|---|
| Sep 7 (3 days) | 111 |
| Sep 14 | 342 |
| Sep 21 | 321 |
| Sep 28 | 279 |
| Oct 5 | 175 |
| Oct 12 | 254 |
| Oct 19 (4 days) | 231 |
Compared with all codes
- Robocalls
- 70%all codes 75%
- Callers with the same code
- 72%all codes 35%
- Rank by complaints
- #19of 461 · top tenth (most complaints)
- FCC complaints, Oct 2025 – Sep 2026
- 17812 about text messages
What the calls were about
Sep 11 – Oct 22, 2026
| Subject | Complaints | |
|---|---|---|
| Medical & prescriptions | 240 14% | |
| Reducing your debt (credit cards, mortgage, student loans) | 200 12% | |
| Calls pretending to be government, businesses, or family and friends | 174 10% | |
| Dropped call or no message | 91 5% | |
| Warranties & protection plans | 40 2% | |
| Home security & alarms | 19 1% |
Where the people who complained live
Sep 11 – Oct 22, 2026
| State | Complaints | |
|---|---|---|
| Tennessee | 1,238 72% | |
| Georgia | 124 7% | |
| Florida | 38 2% | |
| California | 31 2% | |
| Texas | 26 2% |
October 2026 (partial) report · most reported
Consumer reports, not verified by the FTC · source
Source: FTC Do Not Call complaints created Sep 11 – Oct 22, 2026. They are reported by consumers and are not verified by the FTC; caller ID can be spoofed (how we count).
Source: FCC Consumer Complaints data, unwanted calls filed Oct 1, 2025 – Sep 30, 2026, by caller ID; not verified by the FCC.
Area code 423 location and prefixes
| Exchange (NANPA) | Place | County | Prefixes |
|---|---|---|---|
| CHATTNOOGA | Chattanooga | Hamilton County | 183 |
| JOHNSON CY | Johnson City | spans 3 counties | 67 |
| BRISTOL | Bristol | Sullivan County | 38 |
| CLEVELAND | Cleveland | Bradley County | 33 |
| KINGSPORT | Kingsport | spans 2 counties | 32 |
| MORRISTOWN | Morristown | spans 2 counties | 28 |
| ATHENS | Athens | McMinn County | 22 |
| GREENEVL | Greeneville | Greene County | 20 |
| LAFOLLETTE | La Follette | Campbell County | 16 |
| NEWPORT | Newport | Cocke County | 15 |
Plus 65 smaller exchange areas.
Source: NANPA CO codes of Oct 23, 2026; places: U.S. Census Bureau, matched by DialWhere (how).
Is 423 running out of numbers?
Previous forecast (October 2025): 2084, moved earlier by 3 years.
Forecast exhaust year by edition
Source: NANPA NRUF forecast, April 2026 edition.
Who holds 423 prefixes
The five largest of 57 original holders
As listed by NANPA, not today’s carrier.
| Holder (as listed) | Prefixes | |
|---|---|---|
| South Central Bell Tel | 120 15% | |
| Centurylink | 83 11% | |
| New Cingular Wireless PCS, LLC | 80 10% | |
| Verizon Wireless | 80 10% | |
| Onvoy, LLC | 54 7% |
Source: NANPA CO codes of Oct 23, 2026.
Questions about area code 423
What area code is 423?
A Tennessee area code, in service since September 11, 1995.
Where is 423 area code, and what time zone is it in?
Chattanooga, TN; Eastern Time and Central Time.
Why am I getting spam calls from 423?
1,158 FTC complaints from Sep 23 – Oct 22, 2026, most often about medical & prescriptions (not verified by the FTC; caller ID can be spoofed).
Will 423 get a new area code?
NANPA forecasts exhaust in 1Q 2081; no relief planning listed.