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 |
|---|---|---|---|---|---|---|
| — | 641-338 | 8XXX which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | THAYER | IA |
| — | 641-442 | 5XXX6XXX which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | DAVIS CITY | IA |
| — | 641-443 | not yet reported which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | GARDEN GRV | IA |
| — | 641-445 | not yet reported which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | WELDON | IA |
| — | 641-446 | 0XXX which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | LEON | IA |
| — | 641-533 | not yet reported which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | DERBY | IA |
| — | 641-773 | 3XXX8XXX · 2 holders which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | GRANDRIVER | IA |
| — | 641-784 | none assigned yet which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | LAMONI | IA |
| — | 641-788 | 4XXX8XXX · 2 holders which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | BLOCKTON | IA |
| — | 641-873 | not yet reported which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | ALLERTON | IA |
| — | 641-876 | not yet reported which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | LINEVILLE | IA |
| — | 641-897 | not yet reported which blocks → | GRAND RIVER MUTUAL TEL CO | 1888 | MILLERTON | IA |
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.