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 |
|---|---|---|---|---|---|---|
| 2016-09-22 | 413-412 | 0–9 XXXall 10 · 7 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | NORTHADAMS | MA |
| 2008-09-15 | 413-340 | 0–9 XXXall 10 · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | WILLIAMSBG | MA |
| 2005-12-23 | 413-650 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | HOLYOKE | MA |
| 2004-08-13 | 413-349 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | HATFIELD | MA |
| 2002-05-08 | 413-306 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | SPRINGFLD | MA |
| 2001-11-15 | 413-849 | 0XXX1XXX2XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | CHARLEMONT | MA |
| 2001-07-13 | 413-338 | 1XXX3XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | WARREN | MA |
| 2001-07-13 | 413-497 | 1XXX3XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | GILBERTVL | MA |
| 2001-06-21 | 413-994 | 1XXX2XXX3XXX4XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | CHARLEMONT | MA |
| 2001-01-22 | 413-320 | 0–9 XXXall 10 · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | NORTHAMPTN | MA |
| — | 413-239 | 1XXX3XXX5XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | NORTHFIELD | MA |
| — | 413-251 | 1XXX3XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | HINSDALE | MA |
| — | 413-341 | 1XXX3XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | NORTHAMPTN | MA |
| — | 413-459 | 1XXX3XXX5XXX6XXX7XXX8XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | CHICOPEE | MA |
| — | 413-461 | 1XXX3XXX5XXX6XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | AMHERST | MA |
| — | 413-471 | 3XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | CHESTERFLD | MA |
| — | 413-591 | 1XXX3XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | GREATBNGTN | MA |
| — | 413-728 | 1XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | LENOX | MA |
| — | 413-729 | 1XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | WESTFIELD | MA |
| — | 413-853 | 1XXX3XXX5XXX6XXX7XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MA | 4018 | ASHFIELD | MA |
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.