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 |
|---|---|---|---|---|---|---|
| — | 815-333 | 6XXX7XXX9XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | WOODSTOCK | IL |
| — | 815-345 | 0–9 XXXall 10 · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | WOODSTOCK | IL |
| — | 815-346 | not yet reported which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | GARDNER | IL |
| — | 815-352 | 7XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | KANKAKEE | IL |
| — | 815-361 | none assigned yet which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | MANHATTAN | IL |
| — | 815-364 | 7XXX8XXX9XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | MORRIS | IL |
| — | 815-366 | 6XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | OTTAWA | IL |
| — | 815-371 | 8XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | UTICA | IL |
| — | 815-377 | not yet reported which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CRESCENTCY | IL |
| — | 815-380 | 0XXX1XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | STERLING | IL |
| — | 815-401 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | KANKAKEE | IL |
| — | 815-402 | 1XXX2XXX3XXX4XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | GALENA | IL |
| — | 815-412 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | FRANKFORT | IL |
| — | 815-425 | not yet reported which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CRYSTAL LK | IL |
| — | 815-534 | 0–9 XXXall 10 · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | FRANKFORT | IL |
| — | 815-550 | none assigned yet which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | GRANT PARK | IL |
| — | 815-572 | 1XXX2XXX4XXX6XXX7XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | MARENGO | IL |
| — | 815-642 | 2XXX3XXX5XXX6XXX7XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | MINOOKA | IL |
| — | 815-662 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | MOMENCE | IL |
| — | 815-669 | 0XXX1XXX2XXX5XXX6XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | MCHENRY | IL |
| — | 815-671 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | JOLIET | IL |
| — | 815-676 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | PLAINFIELD | IL |
| — | 815-782 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | PLAINFIELD | IL |
| — | 815-846 | not yet reported which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | JOLIET | IL |
| — | 815-881 | 1XXX2XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | OREGON | IL |
| — | 815-927 | 1XXX7XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | JOLIET | IL |
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.