SAN MARCOS — CA
Data last updated: June 25, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| PACIFIC BELL | 9740 | 10 |
| U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | 3 |
| MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | 3 |
| T-MOBILE USA, INC. | 6529 | 2 |
| TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7147 | 2 |