NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

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, all time — NPA 406
QWEST CORPORATION 132
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 119
NEW CINGULAR WIRELESS PCS, LLC 74
ONVOY, LLC - MT 43
TRIANGLE TEL. COOP. ASSN., INC. 39
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 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
— 406-533 4XXX5XXX8XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9636 BUTTE MT
— 406-534 0–9 XXXall 10 · 4 holders which blocks → CHARTER IP ENABLED SERVICES, LLC 792K BILLINGS MT
— 406-535 not yet reported which blocks → MID-RIVERS TELEPHONE COOPERATIVE, INC. 7830 LEWISTOWN MT
— 406-537 not yet reported which blocks → TRIANGLE TEL. COOP. ASSN., INC. 2257 MELVILLE MT
— 406-538 none assigned yet which blocks → QWEST CORPORATION 9636 LEWISTOWN MT
— 406-539 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 BOZEMAN MT
— 406-540 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY, LLC - MT 453F MISSOULA MT
— 406-541 not yet reported which blocks → BLACKFOOT COMMUNICATIONS, INC. - MT 7870 MISSOULA MT
— 406-542 not yet reported which blocks → QWEST CORPORATION 9636 MISSOULA MT
— 406-543 not yet reported which blocks → QWEST CORPORATION 9636 MISSOULA MT
— 406-544 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 MISSOULA MT
— 406-546 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 6564 MISSOULA MT
— 406-547 none assigned yet which blocks → TRIANGLE TEL. COOP. ASSN., INC. 3310 WHSLPHRSPG MT
— 406-548 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9636 BOZEMAN MT
— 406-549 not yet reported which blocks → QWEST CORPORATION 9636 MISSOULA MT
— 406-550 4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NUSO, LLC 732J MISSOULA MT
— 406-553 1XXX3XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 DIVIDE MT
— 406-554 not yet reported which blocks → RANGE TEL COOP INC 2251 NO BROADUS MT
— 406-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MT
— 406-556 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.