CASTROVL — TX
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| SOUTHWESTERN BELL | 9533 | 2 |
| TELNYX LLC | 073H | 1 |
| LEVEL 3 COMMUNICATIONS, LLC - TX | 6114 | 1 |
| TELEPORT COMMUNICATIONS AMERICA, LLC - TX | 7138 | 1 |
| MATRIX TELECOM, LLC. S/I/I TNCI - TX | 7715 | 1 |