Phone numbers in Longmont, Colorado
Longmont has 64 phone prefixes in area codes 303, 720, 983.
Biggest holders: CenturyLink / Lumen, Verizon Wireless, Onvoy. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 31%
- Local phone company 22%
- Internet / business phone carrier 47%
Every prefix in Longmont
Search the first six digits of a number in this list. If it's here, the number started in Longmont with the carrier shown. If it isn't, check the Colorado page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 303-485 | CenturyLink / Lumen | Local phone company | – |
| 303-532 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 303-651 | CenturyLink / Lumen | Local phone company | – |
| 303-652 | CenturyLink / Lumen | Local phone company | – |
| 303-678 | CenturyLink / Lumen | Local phone company | – |
| 303-682 | CenturyLink / Lumen | Local phone company | – |
| 303-684 | CenturyLink / Lumen | Local phone company | – |
| 303-702 | CenturyLink / Lumen | Local phone company | – |
| 303-709 | Verizon Wireless | Mobile carrier | – |
| 303-746 | Verizon Wireless | Mobile carrier | – |
| 303-772 | CenturyLink / Lumen | Local phone company | – |
| 303-774 | CenturyLink / Lumen | Local phone company | – |
| 303-775 | Verizon Wireless | Mobile carrier | – |
| 303-776 | CenturyLink / Lumen | Local phone company | – |
| 303-827 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 303-834 | Verizon Wireless | Mobile carrier | 2006 |
| 303-845 | Teleport Communications America | Internet / business phone carrier | – |
| 303-848 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 720-204 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 720-340 | Verizon Wireless | Mobile carrier | 2009 |
| 720-378 | AT&T Mobility | Mobile carrier | 2010 |
| 720-438 | Onvoy | Internet / business phone carrier | 2006 |
| 720-442 | Bandwidth | Internet / business phone carrier | 2011 |
| 720-453 | T-Mobile (including Sprint) | Mobile carrier | – |
| 720-487 | Telnyx | Internet / business phone carrier | 2016 |
| 720-491 | AT&T Mobility | Mobile carrier | 2011 |
| 720-494 | CenturyLink / Lumen | Local phone company | – |
| 720-526 | AT&T Mobility | Mobile carrier | 2014 |
| 720-534 | Vonage America | Internet / business phone carrier | 2016 |
| 720-552 | Verizon Wireless | Mobile carrier | 2012 |
| 720-597 | Verizon Wireless | Mobile carrier | 2016 |
| 720-600 | Onvoy | Internet / business phone carrier | 2012 |
| 720-652 | CenturyLink / Lumen | Local phone company | – |
| 720-680 | T-Mobile (including Sprint) | Mobile carrier | 2020 |
| 720-684 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 720-698 | Verizon Wireless | Mobile carrier | 2022 |
| 720-713 | Onvoy | Internet / business phone carrier | 2019 |
| 720-714 | Onvoy | Internet / business phone carrier | 2020 |
| 720-718 | CenturyLink / Lumen | Local phone company | 2016 |
| 720-727 | Bandwidth | Internet / business phone carrier | 2018 |
| 720-731 | Level 3 (Lumen) | Internet / business phone carrier | 2019 |
| 720-743 | Bandwidth | Internet / business phone carrier | 2020 |
| 720-745 | Level 3 (Lumen) | Internet / business phone carrier | 2015 |
| 720-759 | Bandwidth | Internet / business phone carrier | 2016 |
| 720-781 | T-Mobile (including Sprint) | Mobile carrier | 2020 |
| 720-804 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 720-815 | Comcast | Internet / business phone carrier | 2017 |
| 720-818 | Verizon Wireless | Mobile carrier | 2017 |
| 720-821 | Onvoy | Internet / business phone carrier | 2021 |
| 720-853 | Bandwidth | Internet / business phone carrier | 2021 |
| 720-864 | CenturyLink / Lumen | Local phone company | – |
| 720-871 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 720-899 | Verizon Wireless | Mobile carrier | 2014 |
| 720-927 | Bandwidth | Internet / business phone carrier | 2019 |
| 720-964 | T-Mobile (including Sprint) | Mobile carrier | 2022 |
| 720-970 | Bandwidth | Internet / business phone carrier | 2024 |
| 720-986 | Bandwidth | Internet / business phone carrier | 2022 |
| 983-200 | Nuso | Internet / business phone carrier | 2023 |
| 983-207 | Onvoy | Internet / business phone carrier | 2024 |
| 983-213 | AT&T Mobility | Mobile carrier | 2024 |
| 983-223 | Onvoy | Internet / business phone carrier | 2026 |
| 983-226 | Onvoy | Internet / business phone carrier | 2025 |
| 983-230 | Onvoy | Internet / business phone carrier | 2026 |
| 983-983 | Onvoy | Internet / business phone carrier | 2023 |
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.