FRONTIER CALIFORNIA INC.
29 prefixes in 661 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 661-423 | LANCASTER | 2319 | — | — |
| 661-465 | BERENDMESA | 4420 | — | Yes |
| 661-536 | GLENNVILLE | 4420 | — | Yes |
| 661-548 | CLFRNHTSPG | 4420 | — | Yes |
| 661-718 | LANCASTER | 2319 | — | Yes |
| 661-722 | LANCASTER | 2319 | — | — |
| 661-723 | LANCASTER | 2319 | — | — |
| 661-724 | LAKEHUGHES | 2319 | — | Yes |
| 661-726 | LANCASTER | 2319 | — | — |
| 661-727 | HI VISTA | 2319 | — | Yes |
| 661-728 | LANCASTER | 2319 | — | Yes |
| 661-729 | LANCASTER | 2319 | — | — |
| 661-762 | MCKITTRICK | 4420 | — | Yes |
| 661-763 | TAFT | 4420 | — | Yes |
| 661-764 | BUTTONWLLW | 4420 | — | Yes |
| 661-765 | TAFT | 4420 | — | Yes |
| 661-766 | CUYAMA | 4420 | — | Yes |
| 661-768 | TAFT | 4420 | — | Yes |
| 661-769 | TAFT | 4420 | — | Yes |
| 661-792 | MCFARLAND | 4420 | — | Yes |
| 661-797 | LOST HILLS | 4420 | — | Yes |
| 661-940 | LANCASTER | 2319 | — | — |
| 661-942 | LANCASTER | 2319 | — | — |
| 661-943 | LANCASTER | 2319 | — | — |
| 661-945 | LANCASTER | 2319 | — | — |
| 661-946 | LANCASTER | 2319 | — | — |
| 661-948 | LANCASTER | 2319 | — | — |
| 661-949 | LANCASTER | 2319 | — | Yes |
| 661-951 | LANCASTER | 2319 | — | — |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.