NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

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.

Most active assignees, all time — NPA 508
LEVEL 3 COMMUNICATIONS, LLC - MA 60
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2004-08-16 508-812 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 NO SWANSEA MA
2004-08-16 508-859 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 LEICESTER MA
2002-06-27 508-603 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 UPTON MA
2002-05-23 508-413 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 8 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 PROVINCETN MA
2002-02-27 508-340 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WORCESTER MA
2001-06-14 508-507 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FRANKLIN MA
2001-04-11 508-203 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FOXBORO MA
2001-04-11 508-570 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FRANKLIN MA
2001-02-16 508-686 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 HOPKINTON MA
2001-02-16 508-734 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WALPOLE MA
2001-02-16 508-738 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 TAUNTON MA
— 508-202 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FRAMINGHAM MA
— 508-210 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 HOLDEN MA
— 508-214 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WELLFLEET MA
— 508-219 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 EASTON MA
— 508-275 4XXX5XXX6XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 HOLLISTON MA
— 508-283 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FRAMINGHAM MA
— 508-306 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 HOLLISTON MA
— 508-313 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BROCKTON MA
— 508-329 1XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WESTBORO MA
— 508-332 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 NANTUCKET MA
— 508-338 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 VINEYRDHVN MA
— 508-365 0XXX4XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WORCESTER MA
— 508-371 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FRAMINGHAM MA
— 508-377 1XXX2XXX3XXX6XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 MILFORD MA
— 508-403 0XXX1XXX2XXX3XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CATAUMET MA
— 508-406 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 MANSFIELD MA
— 508-419 1XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 OSTERVILLE MA
— 508-434 0XXX1XXX2XXX3XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CHARLTON MA
— 508-443 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BRIDGEWTR MA
— 508-444 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FALMOUTH MA
— 508-449 0XXX1XXX2XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 MARLBORO MA
— 508-500 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 MARION MA
— 508-503 1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 PLYMOUTH MA
— 508-534 3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 HYANNIS MA
— 508-536 0XXX1XXX2XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FALL RIVER MA
— 508-556 2XXX5XXX6XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WORCESTER MA
— 508-558 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FALL RIVER MA
— 508-562 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BROCKTON MA
— 508-576 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 NO ATTLEBO MA
— 508-593 0XXX1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CHATHAM MA
— 508-613 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 FRANKLIN MA
— 508-619 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 DENNIS MA
— 508-630 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 MARLBORO MA
— 508-635 4XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WORCESTER MA
— 508-682 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 EASTON MA
— 508-692 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 TAUNTON MA
— 508-709 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 NORTHBORO MA
— 508-714 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 WHITINSVL MA
— 508-715 0XXX1XXX3XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 EBRIDGEWTR MA

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.