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 |
|---|---|---|---|---|---|---|
| 2004-10-05 | 301-302 | 0–9 XXXall 10 · 5 holders which blocks → | METROPCS, INC. | 5562 | HAGERSTOWN | MD |
| — | 301-252 | none assigned yet which blocks → | METROPCS, INC. | 5562 | GAITHERSBG | MD |
| — | 301-305 | none assigned yet which blocks → | METROPCS, INC. | 5562 | FREDERICK | MD |
| — | 301-343 | none assigned yet which blocks → | METROPCS, INC. | 5562 | WSHNGTNZN5 | MD |
| — | 301-366 | 0–9 XXXall 10 · 3 holders which blocks → | METROPCS, INC. | 5562 | GAITHERSBG | MD |
| — | 301-370 | none assigned yet which blocks → | METROPCS, INC. | 5562 | GAITHERSBG | MD |
| — | 301-399 | none assigned yet which blocks → | METROPCS, INC. | 5562 | WALDORF | MD |
| — | 301-440 | none assigned yet which blocks → | METROPCS, INC. | 5562 | WSHNGTNZN5 | MD |
| — | 301-462 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | METROPCS, INC. | 5562 | MYERSVILLE | MD |
| — | 301-536 | 9XXX which blocks → | METROPCS, INC. | 5562 | LEONARDTN | MD |
| — | 301-573 | none assigned yet which blocks → | METROPCS, INC. | 5562 | HAGERSTOWN | MD |
| — | 301-732 | 0–9 XXXall 10 · 5 holders which blocks → | METROPCS, INC. | 5562 | FREDERICK | MD |
| — | 301-748 | none assigned yet which blocks → | METROPCS, INC. | 5562 | FREDERICK | MD |
| — | 301-992 | none assigned yet which blocks → | METROPCS, INC. | 5562 | HAGERSTOWN | MD |
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.