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 |
|---|---|---|---|---|---|---|
| 2025-03-18 | 406-307 | 1XXX which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | CANYON CRK | MT |
| 2013-07-17 | 406-300 | 0–9 XXXall 10 · 6 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | KALISPELL | MT |
| 2012-04-03 | 406-404 | 0–9 XXXall 10 · 4 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | BOZEMAN | MT |
| 2012-04-03 | 406-502 | 1XXX2XXX8XXX · 2 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | HELENA | MT |
| 2012-03-07 | 406-702 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | BILLINGS | MT |
| 2011-07-01 | 406-309 | 0–9 XXXall 10 · 6 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | KALISPELL | MT |
| 2011-01-10 | 406-996 | 1XXX which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | HELENA | MT |
| 2011-01-07 | 406-926 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | MISSOULA | MT |
| 2010-04-09 | 406-415 | 0–9 XXXall 10 · 6 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | DEER LODGE | MT |
| 2009-03-20 | 406-898 | 0–9 XXXall 10 · 4 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | BOZEMAN | MT |
| 2008-10-27 | 406-845 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | CUT BANK | MT |
| 2008-04-08 | 406-513 | 1XXX8XXX9XXX · 2 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | HELENA | MT |
| 2007-02-06 | 406-830 | 0–9 XXXall 10 · 4 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | MISSOULA | MT |
| 2006-09-30 | 406-839 | 0–9 XXXall 10 · 2 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | BILLINGS | MT |
| 2006-03-30 | 406-393 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | SOMERS | MT |
| 2006-02-28 | 406-420 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | BIGFORK | MT |
| — | 406-319 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | POLSON | MT |
| — | 406-330 | 0XXX1XXX2XXX3XXX · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | CLINTON | MT |
| — | 406-422 | 0–9 XXXall 10 · 2 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | HELENA | MT |
| — | 406-493 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | MISSOULA | MT |
| — | 406-534 | 0–9 XXXall 10 · 4 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | BILLINGS | MT |
| — | 406-571 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | FINLEY PT | MT |
| — | 406-709 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | LAKESIDE | MT |
| — | 406-730 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | WHITEFISH | MT |
| — | 406-890 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | KALISPELL | MT |
| — | 406-897 | 0–9 XXXall 10 · 5 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | COLUMBIFLS | 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.