Phone numbers in San Marcos, California
San Marcos has 31 phone prefixes in area codes 442, 760.
Biggest holders: AT&T (local phone), Tpx Communications, MCImetro (Verizon Business). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 16%
- Local phone company 32%
- Internet / business phone carrier 48%
- Phone company 3%
Every prefix in San Marcos
Search the first six digits of a number in this list. If it's here, the number started in San Marcos with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 442-385 | Teleport Communications America | Internet / business phone carrier | 2021 |
| 442-416 | T-Mobile (including Sprint) | Mobile carrier | 2023 |
| 442-472 | Verizon Wireless | Mobile carrier | 2024 |
| 442-503 | Verizon Wireless | Mobile carrier | 2026 |
| 442-515 | Telnyx | Internet / business phone carrier | 2016 |
| 442-655 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 760-204 | 33 Wireless | Mobile carrier | – |
| 760-290 | Tpx Communications | Internet / business phone carrier | – |
| 760-304 | Teleport Communications America | Internet / business phone carrier | – |
| 760-410 | Tpx Communications | Internet / business phone carrier | – |
| 760-471 | AT&T (local phone) | Local phone company | – |
| 760-481 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 760-510 | AT&T (local phone) | Local phone company | – |
| 760-539 | Onvoy | Internet / business phone carrier | – |
| 760-566 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 760-571 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 760-591 | AT&T (local phone) | Local phone company | – |
| 760-593 | AT&T (local phone) | Local phone company | 2001 |
| 760-621 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 760-653 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 760-661 | North County Communication | Phone company | – |
| 760-682 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 760-736 | AT&T (local phone) | Local phone company | – |
| 760-744 | AT&T (local phone) | Local phone company | – |
| 760-750 | AT&T (local phone) | Local phone company | – |
| 760-752 | AT&T (local phone) | Local phone company | – |
| 760-759 | Tpx Communications | Internet / business phone carrier | – |
| 760-761 | AT&T (local phone) | Local phone company | – |
| 760-798 | Comcast | Internet / business phone carrier | – |
| 760-891 | AT&T (local phone) | Local phone company | – |
| 760-916 | MCImetro (Verizon Business) | 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.