NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/21/2026
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 |
|---|---|---|---|---|---|---|
| — | 406-292 | 2XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | JOPLIN | MT |
| — | 406-326 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | REEDPOINT | 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 |
| — | 406-355 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | RUDYARD | MT |
| — | 406-357 | 1XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | CHINOOK | MT |
| — | 406-372 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | KREMLIN | MT |
| — | 406-374 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | MOORE | MT |
| — | 406-376 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | GILDFORD | 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 |
| — | 406-383 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | DODSON | MT |
| — | 406-386 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | HOPPILLIAD | 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 |
| — | 406-423 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | HOBSON | MT |
| — | 406-456 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | SO CHESTER | MT |
| — | 406-462 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | WINIFRED | MT |
| — | 406-473 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | JUDITH GAP | MT |
| — | 406-537 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | MELVILLE | MT |
| — | 406-547 | none assigned yet which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | WHSLPHRSPG | MT |
| — | 406-566 | 7XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | STANFORD | MT |
| — | 406-567 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | DENTON | MT |
| — | 406-572 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | MARTINSDL | MT |
| — | 406-622 | 8XXX9XXX · 2 holders which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | FORTBENTON | MT |
| — | 406-632 | 8XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | HARLOWTON | MT |
| — | 406-654 | 9XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | MALTA | MT |
| — | 406-658 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | SOUTHMALTA | MT |
| — | 406-663 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | RAPELJE | MT |
| — | 406-667 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | BROADVIEW | MT |
| — | 406-669 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | MOLT | MT |
| — | 406-673 | none assigned yet which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | HAYS | MT |
| — | 406-674 | none assigned yet which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | WHITEWATER | MT |
| — | 406-737 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 3310 | GERALDINE | MT |
| — | 406-739 | not yet reported which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | LOMA | MT |
| — | 406-759 | 2XXX9XXX · 2 holders which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | CHESTER | MT |
| — | 406-932 | 7XXX which blocks → | TRIANGLE TEL. COOP. ASSN., INC. | 2257 | BIG TIMBER | MT |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/21/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.