NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026
The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| 2023-08-01 | 307-294 | 0XXX6XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA WY-LLC | 879G | BIG PINEY | WY |
| 2012-08-01 | 307-823 | 0XXX1XXX2XXX3XXX6XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA WY-LLC | 879G | CHEYENNE | WY |
| — | 307-245 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | PINEBLUFFS | WY |
| — | 307-246 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | ALBIN | WY |
| — | 307-347 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | WORLAND | WY |
| — | 307-375 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | WORLAND | WY |
| — | 307-437 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | MIDWEST | WY |
| — | 307-457 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | GAS HILLS | WY |
| — | 307-465 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | NEWCASTLE | WY |
| — | 307-467 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | HULETT | WY |
| — | 307-468 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | UPTON | WY |
| — | 307-544 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | JEFFREY CY | WY |
| — | 307-547 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | BURNS | WY |
| — | 307-649 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | CARPENTER | WY |
| — | 307-738 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | KAYCEE | WY |
| — | 307-746 | none assigned yet which blocks → | RT COMMUNICATIONS | 3410 | NEWCASTLE | WY |
| — | 307-756 | none assigned yet which blocks → | RT COMMUNICATIONS | 3410 | MOORCROFT | WY |
| — | 307-864 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | THERMOPOLS | WY |
| — | 307-876 | not yet reported which blocks → | RT COMMUNICATIONS | 3410 | SHOSHONI | WY |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.