NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026
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 |
|---|---|---|---|---|---|---|
| 2023-02-08 | 618-916 | 0–9 XXXall 10 · 2 holders which blocks → | NUSO, LLC | 732J | HERRIN | IL |
| 2020-09-04 | 618-636 | 0–9 XXXall 10 · 7 holders which blocks → | NUSO, LLC | 478J | ALTON | IL |
| 2013-03-13 | 618-605 | 0–9 XXXall 10 · 3 holders which blocks → | NUSO, LLC | 551G | CARBONDALE | IL |
| 2001-12-06 | 618-879 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | NUSO, LLC | 551G | OLNEY | IL |
| — | 618-403 | 0–9 XXXall 10 · 4 holders which blocks → | NUSO, LLC | 478J | FLORA | IL |
| — | 618-561 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | NUSO, LLC | 732J | CARBONDALE | IL |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.