NumberResearchRecent prefix assignments
334 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/28/2026
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.
Most active assignees, last 30 days
New assignments by month
Sep 2026
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Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| — | 406-460 | 5XXX which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SHELBY | MT |
| — | 406-461 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | HELENA | MT |
| — | 406-462 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | WINIFRED | MT |
| — | 406-463 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | POWER | MT |
| — | 406-464 | 4XXX6XXX · 2 holders which blocks → | MID-RIVERS TEL. COOP., INC. | 2246 | ROY | MT |
| — | 406-465 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | HELENA | 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 |
| — | 406-468 | 1XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | CASCADE | MT |
| — | 406-469 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | PENDROY | MT |
| — | 406-470 | 1XXX2XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | SHELBY | MT |
| — | 406-472 | not yet reported which blocks → | 3 RIVERS TEL. COOP., INC. | 2255 | DUPUYER | MT |
| — | 406-473 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | JUDITH GAP | MT |
| — | 406-474 | not yet reported which blocks → | NEMONT TEL COOP INC | 2247 | FLAXVILLE | MT |
| — | 406-475 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | QWEST CORPORATION | 9636 | HELENA | MT |
| — | 406-476 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | DUTTON | MT |
| — | 406-477 | 1XXX which blocks → | RANGE TEL COOP INC | 2251 | LAME DEER | MT |
| — | 406-478 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | SIDNEY | MT |
| — | 406-480 | 6XXX7XXX8XXX · 3 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | SIDNEY | MT |
| — | 406-482 | 0XXX5XXX which blocks → | QWEST CORPORATION | 9636 | SIDNEY | MT |
| — | 406-483 | not yet reported which blocks → | NEMONT TEL COOP INC | 2247 | DAGMAR | MT |
| — | 406-484 | 4XXX which blocks → | TRI-COUNTY TEL. ASSN., INC. | 2296 | CROOKEDCRK | MT |
| — | 406-485 | 5XXX8XXX · 2 holders which blocks → | MID-RIVERS TEL. COOP., INC. | 2246 | CIRCLE | MT |
| — | 406-486 | not yet reported which blocks → | MID-RIVERS TEL. COOP., INC. | 2246 | FALLON | MT |
| — | 406-487 | none assigned yet which blocks → | NEMONT TEL COOP INC | 2247 | SCOBEY | MT |
| — | 406-488 | not yet reported which blocks → | MID-RIVERS TELEPHONE COOPERATIVE, INC. | 7830 | SIDNEY | MT |
| — | 406-489 | 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SIDNEY | MT |
| — | 406-490 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | BUTTE | MT |
| — | 406-491 | 8XXX9XXX which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BUTTE | MT |
| — | 406-492 | not yet reported which blocks → | BLACKFOOT TEL. COOP., INC. | 2235 | AVON | MT |
| — | 406-493 | 0–9 XXXall 10 · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | MISSOULA | MT |
| — | 406-494 | not yet reported which blocks → | QWEST CORPORATION | 9636 | BUTTE | MT |
| — | 406-495 | none assigned yet which blocks → | QWEST CORPORATION | 9636 | HELENA | MT |
| — | 406-496 | 7XXX which blocks → | QWEST CORPORATION | 9636 | BUTTE | MT |
| — | 406-497 | 0XXX which blocks → | QWEST CORPORATION | 9636 | BUTTE | MT |
| — | 406-498 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | BUTTE | MT |
| — | 406-511 | not yet reported which blocks → | MULTIPLE OCN LISTING | MULT | XXXXXXXXXX | MT |
| — | 406-519 | 0–9 XXXall 10 · 5 holders which blocks → | IP HORIZON LLC | 515J | MISSOULA | MT |
| — | 406-520 | 0XXX1XXX5XXX6XXX · 3 holders which blocks → | HD CARRIER LLC | 321J | ABSAROKEE | MT |
| — | 406-521 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | TOWNSEND | MT |
| — | 406-522 | not yet reported which blocks → | QWEST CORPORATION | 9636 | BOZEMAN | MT |
| — | 406-523 | not yet reported which blocks → | QWEST CORPORATION | 9636 | MISSOULA | MT |
| — | 406-524 | none assigned yet which blocks → | NEMONT TEL COOP INC | 2247 | VLINSTRLPK | MT |
| — | 406-525 | 2XXX5XXX · 2 holders which blocks → | MID-RIVERS TEL. COOP., INC. | 2246 | SO WOLF PT | MT |
| — | 406-526 | none assigned yet which blocks → | NEMONT TEL COOP INC | 2247 | FORT PECK | MT |
| — | 406-527 | 6XXX which blocks → | NEMONT TEL COOP INC | 2247 | SACO | MT |
| — | 406-528 | not yet reported which blocks → | RONAN TEL. CO. | 2252 | RONAN | MT |
| — | 406-530 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MT | 9415 | LAUREL | MT |
| — | 406-531 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | MISSOULA | MT |
| — | 406-532 | not yet reported which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | MISSOULA | MT |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/28/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.