Phone numbers in Colby, Wisconsin
Colby has 6 phone prefixes in area codes 534, 715.
Biggest holders: Level 3 (Lumen), TON80 Communications, Frontier. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 17%
- Local phone company 17%
- Internet / business phone carrier 67%
Every prefix in Colby
Search the first six digits of a number in this list. If it's here, the number started in Colby with the carrier shown. If it isn't, check the Wisconsin page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 534-227 | TON80 Communications | Internet / business phone carrier | 2022 |
| 715-223 | Frontier | Local phone company | – |
| 715-316 | Level 3 (Lumen) | Internet / business phone carrier | 2002 |
| 715-390 | Onvoy | Internet / business phone carrier | 2020 |
| 715-613 | AT&T Mobility | Mobile carrier | – |
| 715-721 | Level 3 (Lumen) | Internet / business phone carrier | 2012 |
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.