Phone numbers in La Crescenta-Montrose, California
La Crescenta-Montrose has 23 phone prefixes in area codes 747, 818.
Biggest holders: AT&T (local phone), T-Mobile (including Sprint), Fractel. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 26%
- Local phone company 26%
- Internet / business phone carrier 48%
Every prefix in La Crescenta-Montrose
Search the first six digits of a number in this list. If it's here, the number started in La Crescenta-Montrose with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 747-218 | T-Mobile (including Sprint) | Mobile carrier | 2016 |
| 747-255 | T-Mobile (including Sprint) | Mobile carrier | 2015 |
| 747-342 | Fractel | Internet / business phone carrier | 2022 |
| 747-371 | T-Mobile (including Sprint) | Mobile carrier | 2024 |
| 747-399 | Fractel | Internet / business phone carrier | 2021 |
| 747-895 | Onvoy | Internet / business phone carrier | – |
| 818-236 | AT&T (local phone) | Local phone company | – |
| 818-248 | AT&T (local phone) | Local phone company | – |
| 818-249 | AT&T (local phone) | Local phone company | – |
| 818-275 | Onvoy | Internet / business phone carrier | 2008 |
| 818-279 | MCImetro (Verizon Business) | Internet / business phone carrier | 2001 |
| 818-306 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 818-330 | Tpx Communications | Internet / business phone carrier | – |
| 818-369 | Matrix Telecom, Llc. S/i/i Tnci | Internet / business phone carrier | – |
| 818-405 | T-Mobile (including Sprint) | Mobile carrier | – |
| 818-418 | AT&T Mobility | Mobile carrier | 2023 |
| 818-541 | AT&T (local phone) | Local phone company | – |
| 818-542 | AT&T (local phone) | Local phone company | – |
| 818-658 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 818-797 | Bandwidth | Internet / business phone carrier | 2006 |
| 818-862 | Level 3 (Lumen) | Internet / business phone carrier | 2006 |
| 818-873 | T-Mobile (including Sprint) | Mobile carrier | 2020 |
| 818-957 | AT&T (local phone) | 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.