Phone numbers in Morristown, Tennessee
Morristown has 28 phone prefixes in area code 423.
Biggest holders: AT&T (local phone), Windstream (PAETEC), AT&T Mobility. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 32%
- Local phone company 29%
- Internet / business phone carrier 39%
Every prefix in Morristown
Search the first six digits of a number in this list. If it's here, the number started in Morristown with the carrier shown. If it isn't, check the Tennessee page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 423-200 | Level 3 (Lumen) | Internet / business phone carrier | 2002 |
| 423-231 | AT&T Mobility | Mobile carrier | – |
| 423-254 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 423-258 | AT&T Mobility | Mobile carrier | – |
| 423-273 | T-Mobile (including Sprint) | Mobile carrier | – |
| 423-277 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 423-289 | T-Mobile (including Sprint) | Mobile carrier | – |
| 423-307 | Windstream (PAETEC) | Internet / business phone carrier | 2005 |
| 423-312 | Verizon Wireless | Mobile carrier | – |
| 423-317 | AT&T (local phone) | Local phone company | – |
| 423-318 | AT&T (local phone) | Local phone company | – |
| 423-353 | Windstream (PAETEC) | Internet / business phone carrier | 2011 |
| 423-438 | Level 3 (Lumen) | Internet / business phone carrier | 2002 |
| 423-492 | AT&T (local phone) | Local phone company | 2011 |
| 423-522 | AT&T (local phone) | Local phone company | 2002 |
| 423-581 | AT&T (local phone) | Local phone company | – |
| 423-585 | AT&T (local phone) | Local phone company | – |
| 423-586 | AT&T (local phone) | Local phone company | – |
| 423-587 | AT&T (local phone) | Local phone company | – |
| 423-616 | Onvoy | Internet / business phone carrier | 2014 |
| 423-621 | Verizon Wireless | Mobile carrier | – |
| 423-690 | Telnyx | Internet / business phone carrier | 2016 |
| 423-714 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 423-736 | Verizon Wireless | Mobile carrier | – |
| 423-748 | AT&T Mobility | Mobile carrier | – |
| 423-759 | Onvoy | Internet / business phone carrier | 2021 |
| 423-839 | Charter / Spectrum | Internet / business phone carrier | – |
| 423-927 | TON80 Communications | Internet / business phone carrier | 2022 |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.