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 |
|---|---|---|---|---|---|---|
| — | 304-223 | 0XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → | CSC VOICE, LLC | 612K | FLAT TOP | WV |
| — | 304-301 | 0–9 XXXall 10 · 2 holders which blocks → | CSC VOICE, LLC | 612K | ATHENS | WV |
| — | 304-306 | 0–9 XXXall 10 · 4 holders which blocks → | CSC VOICE, LLC | 612K | CHRLSTNZN7 | WV |
| — | 304-398 | 0–9 XXXall 10 · 7 holders which blocks → | CSC VOICE, LLC | 612K | NEWMRTNSVL | WV |
| — | 304-501 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | CSC VOICE, LLC | 612K | WAYNE | WV |
| — | 304-520 | 0–9 XXXall 10 · 6 holders which blocks → | CSC VOICE, LLC | 612K | LEWISBURG | WV |
| — | 304-600 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CSC VOICE, LLC | 612K | LETART | WV |
| — | 304-717 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | CSC VOICE, LLC | 612K | RUPERT | WV |
| — | 304-850 | 0–9 XXXall 10 · 5 holders which blocks → | CSC VOICE, LLC | 612K | WILLIAMSTN | WV |
| — | 304-913 | 0–9 XXXall 10 · 4 holders which blocks → | CSC VOICE, LLC | 612K | PRINCETON | WV |
| — | 304-917 | 0–9 XXXall 10 · 6 holders which blocks → | CSC VOICE, LLC | 612K | PRKRSBGZN1 | WV |
| — | 304-971 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | CSC VOICE, LLC | 612K | NEW HAVEN | WV |
| — | 304-973 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | CSC VOICE, LLC | 612K | BELMONT | WV |
| — | 304-977 | 3XXX4XXX6XXX7XXX9XXX · 4 holders which blocks → | CSC VOICE, LLC | 612K | MATOAKA | WV |
| — | 304-978 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | CSC VOICE, LLC | 612K | CLAY | WV |
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.