NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/23/2026
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 |
|---|---|---|---|---|---|---|
| — | 603-387 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | LACONIA | NH |
| — | 603-475 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | SALEM | NH |
| — | 603-481 | 3XXX5XXX7XXX8XXX · 3 holders which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | PLYMOUTH | NH |
| — | 603-490 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | DERRY | NH |
| — | 603-491 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | CONCORD | NH |
| — | 603-493 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | MERRIMACK | NH |
| — | 603-494 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | MERRIMACK | NH |
| — | 603-496 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | CONCORD | NH |
| — | 603-498 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | PORTSMOUTH | NH |
| — | 603-513 | 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | CONCORD | NH |
| — | 603-520 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | LACONIA | NH |
| — | 603-534 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | DOVER | NH |
| — | 603-548 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | DERRY | NH |
| — | 603-558 | 6XXX7XXX9XXX which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | CLAREMONT | NH |
| — | 603-566 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | NASHUA | NH |
| — | 603-716 | 0–9 XXXall 10 · 3 holders which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | MANCHESTER | NH |
| — | 603-731 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | CONCORD | NH |
| — | 603-759 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | NASHUA | NH |
| — | 603-762 | 6XXX7XXX8XXX9XXX · 2 holders which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | KEENE | NH |
| — | 603-770 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | EXETER | NH |
| — | 603-812 | 1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | PORTSMOUTH | NH |
| — | 603-851 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | MANCHESTER | NH |
| — | 603-860 | not yet reported which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | MANCHESTER | NH |
| — | 603-903 | 0–9 XXXall 10 · 4 holders which blocks → | BELL ATLANTIC MOBILE, INC | 6386 | KEENE | NH |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/23/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.