NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/21/2026
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 |
|---|---|---|---|---|---|---|
| — | 406-236 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | NEIHART | MT |
| — | 406-264 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | FORT SHAW | MT |
| — | 406-276 | none assigned yet which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | LIMA | MT |
| — | 406-277 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | BELT | MT |
| — | 406-279 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | VALIER | MT |
| — | 406-463 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | POWER | MT |
| — | 406-466 | 7XXX which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | CHOTEAU | MT |
| — | 406-467 | 0XXX which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | FAIRFIELD | MT |
| — | 406-469 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | PENDROY | MT |
| — | 406-472 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | DUPUYER | MT |
| — | 406-562 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | AUGUSTA | MT |
| — | 406-627 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | EASTCONRAD | MT |
| — | 406-682 | 0XXX which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | ENNIS | MT |
| — | 406-684 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | TWINBRIDGS | MT |
| — | 406-685 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | HARRISON | MT |
| — | 406-733 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | HIGHWOOD | MT |
| — | 406-734 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | CARTER | MT |
| — | 406-735 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | GEYSER | MT |
| — | 406-736 | 2XXX which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | STOCKETT | MT |
| — | 406-738 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | RAYNESFORD | MT |
| — | 406-753 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | BRADY | MT |
| — | 406-835 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | MELROSE | MT |
| — | 406-842 | none assigned yet which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | SHERIDAN | MT |
| — | 406-843 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | VIRGINIACY | MT |
| — | 406-993 | 0XXX8XXX · 2 holders which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | BIG SKY | MT |
| — | 406-995 | 0XXX which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | BIG SKY | MT |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/21/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.