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 |
|---|---|---|---|---|---|---|
| — | 563-423 | not yet reported which blocks → | ACE TEL. ASSN. - IA | 1346 | CLERMONT | IA |
| — | 563-532 | not yet reported which blocks → | ACE TEL. ASSN. - IA | 1346 | OSSIAN | IA |
| — | 563-534 | not yet reported which blocks → | ACE TEL. ASSN. - IA | 1346 | FTATKINSON | IA |
| — | 563-535 | not yet reported which blocks → | ACE TEL. ASSN. - IA | 1346 | WATERVILLE | IA |
| — | 563-544 | not yet reported which blocks → | ACE TEL. ASSN. - IA | 1346 | NEW ALBIN | IA |
| — | 563-546 | not yet reported which blocks → | ACE TEL. ASSN. - IA | 1346 | HIGHLANDVL | IA |
| — | 563-567 | not yet reported which blocks → | ACE TEL. ASSN. - IA | 1346 | CASTALIA | IA |
| — | 563-586 | 8XXX which blocks → | ACE TEL. ASSN. - IA | 1346 | HARPESFRRY | 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.