NumberResearchRecent prefix assignments
347 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/29/2026
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
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
Mar 2026
Feb 2026
Jan 2026
Dec 2025
Nov 2025
Oct 2025
Quick find in this area code:
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| — | 406-310 | 0–9 XXXall 10 · 5 holders which blocks → | BLACKFOOT COMMUNICATIONS, INC. - MT | 7870 | BUTTE | MT |
| — | 406-311 | not yet reported which blocks → | MULTIPLE OCN LISTING | MULT | XXXXXXXXXX | MT |
| — | 406-312 | 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | NUSO, LLC | 478J | BOZEMAN | MT |
| — | 406-315 | 0–9 XXXall 10 · 4 holders which blocks → | SAGEBRUSH CELLULAR, INC. | 443B | GREATFALLS | MT |
| — | 406-317 | 0–9 XXXall 10 · 6 holders which blocks → | TELNYX LLC | 073H | MISSOULA | MT |
| — | 406-319 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | POLSON | MT |
| — | 406-320 | 3XXX which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | ROUNDUP | MT |
| — | 406-321 | 5XXX6XXX7XXX8XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | COLUMBUS | MT |
| — | 406-322 | 2XXX3XXX7XXX · 2 holders which blocks → | QWEST CORPORATION | 9636 | COLUMBUS | MT |
| — | 406-323 | none assigned yet which blocks → | MID-RIVERS TEL. COOP., INC. | 2246 | ROUNDUP | MT |
| — | 406-324 | 0XXX7XXX8XXX9XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | HELENA | MT |
| — | 406-325 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → | NUSO, LLC | 732J | BILLINGS | MT |
| — | 406-326 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | REEDPOINT | MT |
| — | 406-327 | not yet reported which blocks → | QWEST CORPORATION | 9636 | MISSOULA | MT |
| — | 406-328 | 3XXX which blocks → | PROJECT TEL. CO., INC. | 2250 | ABSAROKEE | MT |
| — | 406-329 | not yet reported which blocks → | QWEST CORPORATION | 9636 | MISSOULA | MT |
| — | 406-330 | 0XXX1XXX2XXX3XXX · 3 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | CLINTON | MT |
| — | 406-331 | 1XXX which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | ROUNDUP | MT |
| — | 406-332 | 1XXX2XXX · 2 holders which blocks → | BLACKFOOT TEL. COOP., INC. | 2235 | PABLO | MT |
| — | 406-333 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → | QWEST CORPORATION | 9636 | LIVINGSTON | MT |
| — | 406-335 | not yet reported which blocks → | NORTHERN TEL. COOP., INC. | 2248 | SWEETGRASS | MT |
| — | 406-336 | not yet reported which blocks → | NORTHERN TEL. COOP., INC. | 2248 | NOCUT BANK | MT |
| — | 406-337 | not yet reported which blocks → | NORTHERN TEL. COOP., INC. | 2248 | KEVINOLMNT | MT |
| — | 406-338 | 0XXX which blocks → | SIYEH COMMUNICATIONS | 619J | BROWNING | MT |
| — | 406-339 | not yet reported which blocks → | NORTHERN TEL. COOP., INC. | 2248 | ETHRIDGE | MT |
| — | 406-340 | 0XXX which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | LIMA | MT |
| — | 406-342 | 2XXX which blocks → | RANGE TEL COOP INC | 2251 | HYSHAM | MT |
| — | 406-343 | 3XXX which blocks → | PROJECT TEL. CO., INC. | 2250 | WYOLA | MT |
| — | 406-344 | 0–9 XXXall 10 · 2 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | HAVRE | MT |
| — | 406-345 | 0XXX1XXX4XXX5XXX6XXX · 4 holders which blocks → | MID-RIVERS TELEPHONE COOPERATIVE, INC. | 7830 | GLENDIVE | MT |
| — | 406-347 | not yet reported which blocks → | RANGE TEL COOP INC | 2251 | ROSEBUD | MT |
| — | 406-348 | 1XXX5XXX · 2 holders which blocks → | PROJECT TEL. CO., INC. | 2250 | HUNTLEY | MT |
| — | 406-349 | not yet reported which blocks → | BLACKFOOT TEL. COOP., INC. | 2235 | ALTA | MT |
| — | 406-350 | 4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | LEWISTOWN | MT |
| — | 406-351 | 0XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | FORSYTH | MT |
| — | 406-352 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | BOX ELDER | MT |
| — | 406-353 | 1XXX5XXX6XXX9XXX · 3 holders which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | HARLEM | MT |
| — | 406-354 | not yet reported which blocks → | MID-RIVERS TEL. COOP., INC. | 2246 | ROCK SPG | MT |
| — | 406-355 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | RUDYARD | MT |
| — | 406-356 | 0XXX1XXX5XXX6XXX8XXX · 4 holders which blocks → | QWEST CORPORATION | 9636 | FORSYTH | MT |
| — | 406-357 | 1XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | CHINOOK | MT |
| — | 406-358 | not yet reported which blocks → | MID-RIVERS TEL. COOP., INC. | 2246 | MELSTONE | MT |
| — | 406-359 | 0XXX1XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → | QWEST CORPORATION | 9636 | GLENDIVE | MT |
| — | 406-360 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | HAMILTON | MT |
| — | 406-362 | not yet reported which blocks → | LINCOLN TEL. CO., INC. | 2244 | LINCOLN | MT |
| — | 406-363 | none assigned yet which blocks → | QWEST CORPORATION | 9636 | HAMILTON | MT |
| — | 406-364 | not yet reported which blocks → | NEMONT TEL COOP INC | 2247 | HINSDALE | MT |
| — | 406-365 | 0XXX1XXX · 2 holders which blocks → | QWEST CORPORATION | 9636 | GLENDIVE | MT |
| — | 406-366 | 7XXX8XXX which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | LEWISTOWN | MT |
| — | 406-367 | not yet reported which blocks → | NEMONT TEL COOP INC | 2247 | NO GLASGOW | MT |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/29/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.