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.
Most active assignees, all time — NPA 406
New assignments by month
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Oct 2025
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| — | 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 |
| — | 406-368 | not yet reported which blocks → | LINCOLN TEL. CO., INC. | 2244 | CANYON CRK | MT |
| — | 406-369 | 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | HAMILTON | MT |
| — | 406-370 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | MISSOULA | MT |
| — | 406-372 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | KREMLIN | MT |
| — | 406-373 | 2XXX4XXX8XXX · 2 holders which blocks → | QWEST CORPORATION | 9636 | BILLINGS | MT |
| — | 406-374 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | MOORE | MT |
| — | 406-375 | 1XXX3XXX5XXX · 3 holders which blocks → | QWEST CORPORATION | 9636 | HAMILTON | MT |
| — | 406-376 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | GILDFORD | MT |
| — | 406-377 | not yet reported which blocks → | MID-RIVERS TELEPHONE COOPERATIVE, INC. | 7830 | GLENDIVE | MT |
| — | 406-378 | 8XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | BIG SANDY | MT |
| — | 406-379 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | TURNER | MT |
| — | 406-380 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | LEWISTOWN | MT |
| — | 406-381 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | HAMILTON | MT |
| — | 406-383 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | DODSON | MT |
| — | 406-384 | 1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM | 4222 | BILLINGS | MT |
| — | 406-385 | none assigned yet which blocks → | NEMONT TEL COOP INC | 2247 | WESTBY | MT |
| — | 406-386 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | HOPPILLIAD | MT |
| — | 406-387 | 0XXX1XXX2XXX6XXX7XXX8XXX · 5 holders which blocks → | CENTURYTEL OF MONTANA, INC. DBA CENTURYLINK | 2249 | HUNGRYHORS | MT |
| — | 406-388 | not yet reported which blocks → | QWEST CORPORATION | 9636 | BELGRADE | MT |
| — | 406-390 | none assigned yet which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | SOUTHHAVRE | MT |
| — | 406-391 | 0XXX1XXX2XXX3XXX4XXX6XXX7XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC | 6010 | CUT BANK | MT |
| — | 406-392 | none assigned yet which blocks → | NEMONT TEL COOP INC | 2247 | NO WOLF PT | MT |
| — | 406-394 | 6XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | NORTHHAVRE | MT |
| — | 406-395 | 1XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | SOUTHHAVRE | MT |
| — | 406-397 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | HINGHAM | MT |
| — | 406-398 | none assigned yet which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | NORTHHAVRE | MT |
| — | 406-399 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | SOUTHHAVRE | MT |
| — | 406-410 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | HELENA | MT |
| — | 406-411 | not yet reported which blocks → | MULTIPLE OCN LISTING | MULT | XXXXXXXXXX | MT |
| — | 406-421 | 0XXX2XXX which blocks → | RANGE TEL COOP INC | 2251 | SOMILES CY | MT |
| — | 406-422 | 0–9 XXXall 10 · 2 holders which blocks → | CHARTER IP ENABLED SERVICES, LLC | 792K | HELENA | MT |
| — | 406-423 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | HOBSON | MT |
| — | 406-425 | 5XXX6XXX7XXX8XXX · 2 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT | 6564 | RED LODGE | 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.