Phone numbers in Casper, Wyoming
Casper has 40 phone prefixes in area code 307.
Biggest holders: CenturyLink / Lumen, Verizon Wireless, Level 3 (Lumen). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 30%
- Local phone company 42%
- Internet / business phone carrier 28%
Every prefix in Casper
Search the first six digits of a number in this list. If it's here, the number started in Casper with the carrier shown. If it isn't, check the Wyoming page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 307-215 | Bandwidth | Internet / business phone carrier | 2001 |
| 307-224 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 307-232 | CenturyLink / Lumen | Local phone company | – |
| 307-233 | CenturyLink / Lumen | Local phone company | – |
| 307-234 | CenturyLink / Lumen | Local phone company | – |
| 307-235 | CenturyLink / Lumen | Local phone company | – |
| 307-237 | CenturyLink / Lumen | Local phone company | – |
| 307-243 | Onvoy | Internet / business phone carrier | – |
| 307-247 | AT&T Mobility | Mobile carrier | – |
| 307-251 | Verizon Wireless | Mobile carrier | 2006 |
| 307-253 | CenturyLink / Lumen | Local phone company | 2008 |
| 307-258 | Verizon Wireless | Mobile carrier | – |
| 307-259 | Verizon Wireless | Mobile carrier | – |
| 307-261 | CenturyLink / Lumen | Local phone company | – |
| 307-262 | Verizon Wireless | Mobile carrier | – |
| 307-265 | CenturyLink / Lumen | Local phone company | – |
| 307-266 | CenturyLink / Lumen | Local phone company | – |
| 307-267 | AT&T Mobility | Mobile carrier | – |
| 307-268 | CenturyLink / Lumen | Local phone company | – |
| 307-277 | Verizon Wireless | Mobile carrier | 2003 |
| 307-301 | IP Horizon | Internet / business phone carrier | 2023 |
| 307-315 | Charter / Spectrum | Internet / business phone carrier | 2007 |
| 307-333 | Nuso | Internet / business phone carrier | – |
| 307-337 | Charter / Spectrum | Internet / business phone carrier | 2011 |
| 307-377 | Union Telephone | Local phone company | – |
| 307-394 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 307-439 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 307-441 | Verizon Wireless | Mobile carrier | – |
| 307-452 | Onvoy | Internet / business phone carrier | 2024 |
| 307-458 | Boost / Virgin Mobile | Mobile carrier | 2021 |
| 307-462 | Level 3 (Lumen) | Internet / business phone carrier | 2002 |
| 307-472 | CenturyLink / Lumen | Local phone company | – |
| 307-473 | CenturyLink / Lumen | Local phone company | – |
| 307-485 | T-Mobile (including Sprint) | Mobile carrier | 2025 |
| 307-577 | CenturyLink / Lumen | Local phone company | – |
| 307-702 | Union Telephone | Local phone company | 2002 |
| 307-724 | Union Telephone | Local phone company | 2003 |
| 307-776 | Vonage America | Internet / business phone carrier | 2018 |
| 307-797 | AT&T Mobility | Mobile carrier | 2001 |
| 307-995 | CenturyLink / Lumen | Local phone company | – |
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.