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 |
|---|---|---|---|---|---|---|
| 2014-06-18 | 516-442 | 0–9 XXXall 10 · 4 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN06 | NY |
| 2014-06-18 | 516-513 | 0–9 XXXall 10 · 6 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN08 | NY |
| 2012-10-18 | 516-595 | 0–9 XXXall 10 · 6 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN08 | NY |
| 2012-04-24 | 516-544 | 0–9 XXXall 10 · 6 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN06 | NY |
| 2012-04-24 | 516-597 | 0–9 XXXall 10 · 7 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN08 | NY |
| 2012-03-13 | 516-427 | 0–9 XXXall 10 · 2 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN05 | NY |
| 2008-08-18 | 516-441 | 0–9 XXXall 10 · 6 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN01 | NY |
| 2007-02-24 | 516-307 | 0–9 XXXall 10 · 5 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN05 | NY |
| 2005-04-19 | 516-665 | 0–9 XXXall 10 · 5 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN06 | NY |
| 2003-12-01 | 516-208 | 0–9 XXXall 10 · 4 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN06 | NY |
| 2001-04-02 | 516-495 | 0–9 XXXall 10 · 7 holders which blocks → | CSC VOICE, LLC | 612K | NASSAUZN08 | NY |
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.