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.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| — | 608-344 | 2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → | UNITED STATES CELLULAR - WI | 6274 | TOMAH | WI |
| — | 608-369 | 4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | UNITED STATES CELLULAR - WI | 6274 | WESTFIELD | WI |
| — | 608-386 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | LA CROSSE | WI |
| — | 608-393 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | BARABOO | WI |
| — | 608-403 | 0–9 XXXall 10 · 4 holders which blocks → | UNITED STATES CELLULAR - WI | 6274 | ADAMS | WI |
| — | 608-426 | 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | UNITED STATES CELLULAR - WI | 6274 | MONROE | WI |
| — | 608-432 | 0–9 XXXall 10 · 5 holders which blocks → | UNITED STATES CELLULAR - WI | 6274 | WISCONDLLS | WI |
| — | 608-444 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MADISON | WI |
| — | 608-513 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MADISON | WI |
| — | 608-516 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MADISON | WI |
| — | 608-547 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MAUSTON | WI |
| — | 608-548 | 9XXX which blocks → | UNITED STATES CELLULAR - WI | 6274 | MAUSTON | WI |
| — | 608-558 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MONROE | WI |
| — | 608-574 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | DODGEVILLE | WI |
| — | 608-575 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MADISON | WI |
| — | 608-576 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MADISON | WI |
| — | 608-604 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | RICHLD CTR | WI |
| — | 608-606 | 6XXX7XXX8XXX · 3 holders which blocks → | UNITED STATES CELLULAR - WI | 6274 | VIROQUA | WI |
| — | 608-697 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | PORTAGE | WI |
| — | 608-712 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | MADISON | WI |
| — | 608-732 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | PLATTEVL | WI |
| — | 608-751 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | JANESVILLE | WI |
| — | 608-778 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | PLATTEVL | WI |
| — | 608-790 | 9XXX which blocks → | UNITED STATES CELLULAR - WI | 6274 | LA CROSSE | WI |
| — | 608-792 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | LA CROSSE | WI |
| — | 608-963 | none assigned yet which blocks → | UNITED STATES CELLULAR - WI | 6274 | BARABOO | WI |
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.