Phone numbers in Calimesa, California
Calimesa has 16 phone prefixes in area codes 840, 909.
Biggest holders: T-Mobile (including Sprint), Frontier, Bandwidth. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 38%
- Local phone company 31%
- Internet / business phone carrier 31%
Every prefix in Calimesa
Search the first six digits of a number in this list. If it's here, the number started in Calimesa with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 840-219 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 840-223 | Bandwidth | Internet / business phone carrier | 2022 |
| 840-253 | T-Mobile (including Sprint) | Mobile carrier | 2024 |
| 909-316 | Bandwidth | Internet / business phone carrier | 2015 |
| 909-372 | Peerless Network Of California | Internet / business phone carrier | 2013 |
| 909-446 | Frontier | Local phone company | – |
| 909-500 | Onvoy | Internet / business phone carrier | – |
| 909-504 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 909-570 | AT&T (local phone) | Local phone company | – |
| 909-768 | T-Mobile (including Sprint) | Mobile carrier | 2017 |
| 909-769 | AT&T Mobility | Mobile carrier | 2019 |
| 909-790 | Frontier | Local phone company | – |
| 909-795 | Frontier | Local phone company | – |
| 909-797 | Frontier | Local phone company | – |
| 909-845 | T-Mobile (including Sprint) | Mobile carrier | 2020 |
| 909-918 | Level 3 (Lumen) | Internet / business phone carrier | – |
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.