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.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| 2009-06-10 | 410-390 | 0–9 XXXall 10 · 6 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | OCEAN CITY | MD |
| — | 410-423 | not yet reported which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | COLUMBIA | MD |
| — | 410-427 | not yet reported which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | TOWSON | MD |
| — | 410-510 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | FORK | MD |
| — | 410-513 | 4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | PARKVILLE | MD |
| — | 410-559 | 1XXX4XXX6XXX7XXX9XXX · 5 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | PIKESVILLE | MD |
| — | 410-564 | 1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | ELKRIDGE | MD |
| — | 410-568 | 5XXX7XXX8XXX9XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | COCKEYSVL | MD |
| — | 410-649 | 9XXX which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | BALTIMORE | MD |
| — | 410-689 | 5XXX8XXX9XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | GLENBURNIE | MD |
| — | 410-776 | 0XXX1XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | BEL AIR | MD |
| — | 410-818 | 0XXX3XXX4XXX6XXX7XXX8XXX9XXX which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | CATONSVL | MD |
| — | 410-843 | not yet reported which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | BALTIMORE | MD |
| — | 410-951 | not yet reported which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | BALTIMORE | MD |
| — | 410-972 | 1XXX5XXX6XXX7XXX8XXX9XXX which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | ANNAPOLIS | MD |
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.