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 |
|---|---|---|---|---|---|---|
| — | 406-576 | 1XXX7XXX9XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | CONRAD | MT |
| — | 406-580 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BOZEMAN | MT |
| — | 406-593 | 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BUTTE | MT |
| — | 406-596 | none assigned yet which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | DILLON | MT |
| — | 406-597 | 6XXX8XXX which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SHELBY | MT |
| — | 406-660 | 3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | DILLON | MT |
| — | 406-691 | 4XXX7XXX8XXX9XXX · 4 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | ANACONDA | MT |
| — | 406-699 | 1XXX7XXX8XXX9XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | HARDIN | MT |
| — | 406-749 | 2XXX3XXX4XXX5XXX7XXX8XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | COLSTRIP | MT |
| — | 406-790 | 1XXX4XXX5XXX9XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | CULBERTSON | MT |
| — | 406-799 | none assigned yet which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | GREATFALLS | MT |
| — | 406-818 | 0XXX1XXX4XXX5XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | RED LODGE | MT |
| — | 406-824 | none assigned yet which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | STIGNATIUS | MT |
| — | 406-850 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BILLINGS | MT |
| — | 406-851 | 0–9 XXXall 10 · 6 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | MILES CITY | MT |
| — | 406-855 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BILLINGS | MT |
| — | 406-860 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BILLINGS | MT |
| — | 406-861 | none assigned yet which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BILLINGS | MT |
| — | 406-891 | 2XXX4XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BAKER | MT |
| — | 406-899 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | GREATFALLS | MT |
| — | 406-945 | 7XXX8XXX9XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | HAVRE | MT |
| — | 406-949 | 4XXX9XXX which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | TOWNSEND | MT |
| — | 406-951 | 7XXX8XXX9XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | MILES CITY | MT |
| — | 406-989 | 2XXX9XXX which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | W GLENDIVE | 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.