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 |
|---|---|---|---|---|---|---|
| — | 406-693 | 0XXX1XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | WARM SPG | MT |
| — | 406-721 | not yet reported which blocks → | QWEST CORPORATION | 9636 | MISSOULA | MT |
| — | 406-723 | not yet reported which blocks → | QWEST CORPORATION | 9636 | BUTTE | MT |
| — | 406-727 | not yet reported which blocks → | QWEST CORPORATION | 9636 | GREATFALLS | MT |
| — | 406-728 | not yet reported which blocks → | QWEST CORPORATION | 9636 | MISSOULA | MT |
| — | 406-732 | 0XXX1XXX2XXX3XXX6XXX7XXX8XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | ST MARY | MT |
| — | 406-747 | 0XXX2XXX4XXX6XXX7XXX8XXX which blocks → | QWEST CORPORATION | 9636 | FAIRVIEW | MT |
| — | 406-748 | 0XXX1XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | QWEST CORPORATION | 9636 | COLSTRIP | MT |
| — | 406-761 | not yet reported which blocks → | QWEST CORPORATION | 9636 | GREATFALLS | MT |
| — | 406-763 | 0XXX1XXX2XXX3XXX6XXX7XXX8XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | GALATNGTWY | MT |
| — | 406-771 | not yet reported which blocks → | QWEST CORPORATION | 9636 | GREATFALLS | MT |
| — | 406-777 | 6XXX8XXX which blocks → | QWEST CORPORATION | 9636 | STEVENSVL | MT |
| — | 406-782 | not yet reported which blocks → | QWEST CORPORATION | 9636 | BUTTE | MT |
| — | 406-791 | not yet reported which blocks → | QWEST CORPORATION | 9636 | GREATFALLS | MT |
| — | 406-795 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | QWEST CORPORATION | 9636 | WIBAUX | MT |
| — | 406-797 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX9XXX which blocks → | QWEST CORPORATION | 9636 | ANACONDA | MT |
| — | 406-821 | 5XXX6XXX7XXX8XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | DARBY | MT |
| — | 406-823 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → | QWEST CORPORATION | 9636 | LIVINGSTON | MT |
| — | 406-829 | not yet reported which blocks → | QWEST CORPORATION | 9636 | MISSOULA | MT |
| — | 406-838 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | QWEST CORPORATION | 9636 | COOKE CITY | MT |
| — | 406-841 | none assigned yet which blocks → | QWEST CORPORATION | 9636 | HELENA | MT |
| — | 406-846 | 0XXX4XXX5XXX6XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | DEER LODGE | MT |
| — | 406-848 | 0XXX1XXX3XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → | QWEST CORPORATION | 9636 | GARDINER | MT |
| — | 406-866 | 0XXX1XXX6XXX8XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | GREATFALLS | MT |
| — | 406-873 | 0XXX1XXX6XXX7XXX8XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | CUT BANK | MT |
| — | 406-888 | 0XXX1XXX2XXX3XXX4XXX6XXX8XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | W GLACIER | MT |
| — | 406-896 | not yet reported which blocks → | QWEST CORPORATION | 9636 | BILLINGS | MT |
| — | 406-933 | 3XXX4XXX which blocks → | QWEST CORPORATION | 9636 | HELENA | MT |
| — | 406-961 | 2XXX6XXX7XXX9XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | HAMILTON | MT |
| — | 406-962 | 0XXX1XXX2XXX5XXX6XXX7XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | JOLIET | MT |
| — | 406-964 | 2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | GREATFALLS | MT |
| — | 406-994 | not yet reported which blocks → | QWEST CORPORATION | 9636 | BOZEMAN | 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.