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 734
LEVEL 3 COMMUNICATIONS, LLC - MI 42
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
2015-02-04 734-418 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ANN ARBOR MI
2012-02-15 734-343 0–9 XXXall 10 · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 LIVONIA MI
2006-09-26 734-726 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 DEXTER MI
2005-09-12 734-388 0XXX1XXX2XXX4XXX5XXX6XXX8XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 DEXTER MI
2005-08-23 734-606 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEW BOSTON MI
2004-12-27 734-217 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 YPSILANTI MI
2002-02-27 734-752 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 TRENTON MI
2001-12-06 734-719 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CHELSEA MI
2001-05-10 734-364 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MAYBEE MI
2001-05-01 734-720 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WYANDOTTE MI
— 734-238 2XXX3XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WAYNE MI
— 734-239 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ANN ARBOR MI
— 734-259 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 PLYMOUTH MI
— 734-268 0XXX1XXX2XXX3XXX5XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 DEXTER MI
— 734-272 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ANN ARBOR MI
— 734-299 0XXX1XXX3XXX4XXX6XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CARLETON MI
— 734-322 0XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MONROE MI
— 734-328 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 BELLEVILLE MI
— 734-337 4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 YPSILANTI MI
— 734-344 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MONROE MI
— 734-348 2XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 FLAT ROCK MI
— 734-393 0–9 XXXall 10 · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 LOSTPNNSUL MI
— 734-437 1XXX4XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 LIVONIA MI
— 734-443 0XXX2XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEW BOSTON MI
— 734-446 3XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 PLYMOUTH MI
— 734-471 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROCKWOOD MI
— 734-493 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 TRENTON MI
— 734-494 0XXX2XXX3XXX5XXX6XXX7XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROMULUS MI
— 734-526 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MILAN MI
— 734-532 0XXX2XXX3XXX4XXX5XXX6XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROMULUS MI
— 734-556 0XXX2XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WYANDOTTE MI
— 734-557 0XXX1XXX2XXX3XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 YPSILANTI MI
— 734-642 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 TRENTON MI
— 734-681 0XXX1XXX2XXX3XXX5XXX6XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MILAN MI
— 734-732 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 BELLEVILLE MI
— 734-736 0XXX1XXX2XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WAYNE MI
— 734-785 0XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WYANDOTTE MI
— 734-786 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ANN ARBOR MI
— 734-843 0XXX1XXX2XXX3XXX5XXX6XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEW BOSTON MI
— 734-862 0XXX2XXX3XXX4XXX5XXX6XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 PLYMOUTH MI
— 734-864 2XXX3XXX6XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ANN ARBOR MI
— 734-956 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 LIVONIA MI

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.