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 |
|---|---|---|---|---|---|---|
| 2016-12-22 | 585-448 | 0–9 XXXall 10 · 3 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ROCHESTER | NY |
| 2016-08-15 | 585-404 | 0–9 XXXall 10 · 7 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | HENRIETTA | NY |
| 2014-10-17 | 585-434 | 0–9 XXXall 10 · 3 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ROCHESTER | NY |
| 2010-05-13 | 585-250 | 0–9 XXXall 10 · 4 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | BATAVIA | NY |
| 2010-05-13 | 585-270 | 0–9 XXXall 10 · 5 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ROCHESTER | NY |
| 2006-10-18 | 585-653 | 0–9 XXXall 10 · 6 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ARCADE | NY |
| 2006-10-17 | 585-572 | 0–9 XXXall 10 · 6 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | LIVONIA | NY |
| 2006-10-05 | 585-299 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | CHURCHVL | NY |
| 2005-05-25 | 585-204 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | DANSVILLE | NY |
| 2005-03-23 | 585-558 | 0–9 XXXall 10 · 7 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | WARSAW | NY |
| — | 585-207 | 0–9 XXXall 10 · 5 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | FILLMORE | NY |
| — | 585-283 | 0–9 XXXall 10 · 6 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ALBION | NY |
| — | 585-294 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | CALEDONIA | NY |
| — | 585-318 | 0–9 XXXall 10 · 7 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | MEDINA | NY |
| — | 585-319 | 0–9 XXXall 10 · 2 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ROCHESTER | NY |
| — | 585-355 | 0–9 XXXall 10 · 2 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ROCHESTER | NY |
| — | 585-366 | 0–9 XXXall 10 · 6 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | HILTON | NY |
| — | 585-418 | 4XXX5XXX9XXX · 3 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | E PEMBROKE | NY |
| — | 585-438 | 0–9 XXXall 10 · 9 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | AVON | NY |
| — | 585-563 | 0–9 XXXall 10 · 3 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ROCHESTER | NY |
| — | 585-636 | 0–9 XXXall 10 · 7 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | HAMLIN | NY |
| — | 585-708 | 0–9 XXXall 10 · 5 holders which blocks → | TWC IP ENABLED SERVICES, LLC | 793K | ATTICA | 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.