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 |
|---|---|---|---|---|---|---|
| 2012-08-13 | 310-299 | 0–9 XXXall 10 · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | BEVERLYHLS | CA |
| 2005-12-29 | 310-775 | 0–9 XXXall 10 · 7 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | W ANGELES | CA |
| 2005-09-29 | 310-294 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | TORRANCE | CA |
| 2005-09-29 | 310-295 | 0–9 XXXall 10 · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | W ANGELES | CA |
| 2004-11-17 | 310-984 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | SAN PEDRO | CA |
| 2001-05-03 | 310-483 | 0–9 XXXall 10 · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | TORRANCE | CA |
| — | 310-356 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | EL SEGUNDO | CA |
| — | 310-401 | 0–9 XXXall 10 · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | SNMN SNMN | CA |
| — | 310-402 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | BEVERLYHLS | CA |
| — | 310-464 | 1XXX2XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | CMTN GRDN | CA |
| — | 310-469 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | EL SEGUNDO | CA |
| — | 310-491 | 4XXX6XXX8XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | INGLEWOOD | CA |
| — | 310-494 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | MALIBU | CA |
| — | 310-499 | 2XXX3XXX6XXX8XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | BEVERLYHLS | CA |
| — | 310-597 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | W ANGELES | CA |
| — | 310-622 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | W ANGELES | CA |
| — | 310-626 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | LOMITA | CA |
| — | 310-691 | 0–9 XXXall 10 · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | BEVERLYHLS | CA |
| — | 310-733 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | CULVERCITY | CA |
| — | 310-773 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | SNMN MRVS | CA |
| — | 310-878 | 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | CMTN GRDN | CA |
| — | 310-933 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | CMTN CMTN | CA |
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.