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 |
|---|---|---|---|---|---|---|
| 2013-11-08 | 406-601 | 0–9 XXXall 10 · 7 holders which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | BILLINGS | MT |
| 2013-11-08 | 406-602 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | BOZEMAN | MT |
| 2013-11-08 | 406-603 | 0XXX4XXX · 2 holders which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | HELENA | MT |
| 2013-11-08 | 406-607 | 0–9 XXXall 10 · 4 holders which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | KALISPELL | MT |
| 2011-07-15 | 406-604 | 0–9 XXXall 10 · 5 holders which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | GREATFALLS | MT |
| — | 406-310 | 0–9 XXXall 10 · 5 holders which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | BUTTE | MT |
| — | 406-532 | not yet reported which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | MISSOULA | MT |
| — | 406-541 | not yet reported which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | MISSOULA | MT |
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.