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 |
|---|---|---|---|---|---|---|
| 2024-02-28 | 920-957 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | FONDDU LAC | WI |
| 2022-04-29 | 920-580 | 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | OSHKOSH | WI |
| 2022-02-09 | 920-714 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | APPLETON | WI |
| 2021-08-04 | 920-701 | 1XXX2XXX3XXX4XXX7XXX9XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | LOMIRA | WI |
| 2015-03-06 | 920-939 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | APPLETON | WI |
| 2014-05-16 | 920-815 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | APPLETON | WI |
| 2010-08-06 | 920-903 | 0–9 XXXall 10 · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | APPLETON | WI |
| 2005-12-03 | 920-603 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | STURGEONBY | WI |
| 2001-08-09 | 920-265 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | GREEN BAY | WI |
| 2001-08-02 | 920-256 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | STURGEONBY | WI |
| 2001-04-18 | 920-313 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | LOMIRA | WI |
| 2001-04-18 | 920-316 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → | T-MOBILE USA, INC. | 6529 | OOSTBURG | WI |
| 2001-04-09 | 920-277 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | APPLETON | WI |
| — | 920-203 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | OSHKOSH | WI |
| — | 920-205 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | APPLETON | WI |
| — | 920-217 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | GREEN BAY | WI |
| — | 920-222 | 8XXX which blocks → | T-MOBILE USA, INC. | 6529 | LAKE MILLS | WI |
| — | 920-251 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | FONDDU LAC | WI |
| — | 920-297 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | LAKE MILLS | WI |
| — | 920-318 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | BEAVER DAM | WI |
| — | 920-371 | 5XXX9XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | GREEN BAY | WI |
| — | 920-374 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | MANITOWOC | WI |
| — | 920-375 | 1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | FONDDU LAC | WI |
| — | 920-571 | 0XXX1XXX2XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | MANITOWOC | WI |
| — | 920-605 | 1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 7 holders which blocks → | T-MOBILE USA, INC. | 6529 | JEFFERSON | WI |
| — | 920-681 | 9XXX which blocks → | T-MOBILE USA, INC. | 6529 | MANITOWOC | WI |
| — | 920-747 | 1XXX2XXX4XXX5XXX6XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | JEFFERSON | WI |
| — | 920-786 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | HORICON | WI |
| — | 920-791 | 1XXX2XXX3XXX5XXX7XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | BEAVER DAM | WI |
| — | 920-941 | 1XXX2XXX3XXX4XXX6XXX8XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | WATERTOWN | 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.