Phone numbers in El Segundo, California
El Segundo has 57 phone prefixes in area codes 310, 424.
Biggest holders: AT&T (local phone), Teleport Communications America, Level 3 (Lumen). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 12%
- Local phone company 42%
- Internet / business phone carrier 44%
- Paging service 2%
Every prefix in El Segundo
Search the first six digits of a number in this list. If it's here, the number started in El Segundo with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 310-227 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 310-252 | AT&T (local phone) | Local phone company | – |
| 310-321 | Tpx Communications | Internet / business phone carrier | – |
| 310-322 | AT&T (local phone) | Local phone company | – |
| 310-333 | AT&T (local phone) | Local phone company | – |
| 310-334 | AT&T (local phone) | Local phone company | – |
| 310-335 | AT&T (local phone) | Local phone company | – |
| 310-336 | AT&T (local phone) | Local phone company | – |
| 310-341 | Teleport Communications America | Internet / business phone carrier | – |
| 310-343 | Teleport Communications America | Internet / business phone carrier | – |
| 310-356 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 310-364 | AT&T (local phone) | Local phone company | – |
| 310-414 | AT&T (local phone) | Local phone company | – |
| 310-416 | AT&T (local phone) | Local phone company | – |
| 310-426 | AT&T (local phone) | Local phone company | – |
| 310-469 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 310-524 | AT&T (local phone) | Local phone company | – |
| 310-529 | AT&T Mobility | Mobile carrier | – |
| 310-535 | AT&T (local phone) | Local phone company | – |
| 310-563 | AT&T (local phone) | Local phone company | – |
| 310-565 | Teleport Communications America | Internet / business phone carrier | 2020 |
| 310-606 | AT&T (local phone) | Local phone company | – |
| 310-607 | AT&T (local phone) | Local phone company | – |
| 310-615 | AT&T (local phone) | Local phone company | – |
| 310-616 | AT&T (local phone) | Local phone company | – |
| 310-640 | AT&T (local phone) | Local phone company | – |
| 310-647 | AT&T (local phone) | Local phone company | – |
| 310-648 | AT&T (local phone) | Local phone company | – |
| 310-653 | AT&T (local phone) | Local phone company | 2005 |
| 310-658 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 310-662 | AT&T (local phone) | Local phone company | – |
| 310-726 | AT&T (local phone) | Local phone company | – |
| 310-744 | Teleport Communications America | Internet / business phone carrier | – |
| 310-760 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 310-765 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 310-797 | American Messaging Services | Paging service | – |
| 310-906 | IP Horizon | Internet / business phone carrier | – |
| 310-955 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 310-964 | AT&T (local phone) | Local phone company | – |
| 424-217 | T-Mobile (including Sprint) | Mobile carrier | 2007 |
| 424-218 | Tpx Communications | Internet / business phone carrier | 2007 |
| 424-220 | Peerless Network Of California | Internet / business phone carrier | – |
| 424-225 | AT&T Mobility | Mobile carrier | 2007 |
| 424-277 | Level 3 (Lumen) | Internet / business phone carrier | 2011 |
| 424-290 | Bandwidth | Internet / business phone carrier | 2013 |
| 424-301 | MCImetro (Verizon Business) | Internet / business phone carrier | 2015 |
| 424-321 | T-Mobile (including Sprint) | Mobile carrier | 2013 |
| 424-367 | Level 3 (Lumen) | Internet / business phone carrier | 2014 |
| 424-397 | Peerless Network Of California | Internet / business phone carrier | 2015 |
| 424-405 | Verizon Wireless | Mobile carrier | 2017 |
| 424-423 | Teleport Communications America | Internet / business phone carrier | 2016 |
| 424-499 | Bandwidth | Internet / business phone carrier | 2019 |
| 424-502 | Bandwidth | Internet / business phone carrier | 2019 |
| 424-544 | Fractel | Internet / business phone carrier | 2022 |
| 424-557 | Verizon Wireless | Mobile carrier | 2025 |
| 424-678 | Teleport Communications America | Internet / business phone carrier | 2021 |
| 424-850 | 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.