NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026
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 |
|---|---|---|---|---|---|---|
| 2025-03-20 | 641-991 | 1XXX8XXX9XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | OSCEOLA | IA |
| 2024-07-31 | 641-674 | 0XXX3XXX7XXX9XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | CENTERVL | IA |
| 2024-07-18 | 641-657 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX which blocks → | T-MOBILE USA, INC. | 6529 | HAMPTON | IA |
| 2022-04-28 | 641-255 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | MASON CITY | IA |
| 2022-04-28 | 641-261 | 0–9 XXXall 10 · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | TOLEDO | IA |
| 2022-01-13 | 641-517 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | OSKALOOSA | IA |
| 2018-03-06 | 641-548 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → | T-MOBILE USA, INC. | 6529 | MASON CITY | IA |
| 2018-03-06 | 641-808 | 0XXX1XXX4XXX8XXX9XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | COLO | IA |
| 2006-03-24 | 641-909 | 0XXX2XXX4XXX8XXX9XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | LAKE MILLS | IA |
| 2005-12-31 | 641-251 | 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 7 holders which blocks → | T-MOBILE USA, INC. | 6529 | FORESTCITY | IA |
| 2005-06-17 | 641-903 | 0–9 XXXall 10 · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | MASON CITY | IA |
| 2001-08-02 | 641-210 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | MASON CITY | IA |
| 2001-05-23 | 641-328 | 0–9 XXXall 10 · 7 holders which blocks → | T-MOBILE USA, INC. | 6529 | MARSHALLTN | IA |
| 2001-05-15 | 641-233 | 5XXX6XXX7XXX8XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | FAIRFIELD | IA |
| 2001-02-09 | 641-455 | 0XXX2XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | OTTUMWA | IA |
| — | 641-318 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | KNOXVILLE | IA |
| — | 641-416 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | PELLA | IA |
| — | 641-417 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | NEWTON | IA |
| — | 641-504 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | OSKALOOSA | IA |
| — | 641-510 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | GRINNELL | IA |
| — | 641-781 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → | T-MOBILE USA, INC. | 6529 | NEWTON | IA |
| — | 641-831 | 1XXX2XXX6XXX7XXX8XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | NEWTON | IA |
| — | 641-861 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | PELLA | IA |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.