NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

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 505
LEVEL 3 COMMUNICATIONS, LLC - NM 17
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
2021-04-30 505-477 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 SANTA FE NM
2017-01-16 505-772 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 SANTA FE NM
2014-09-15 505-985 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2013-11-04 505-596 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2013-05-28 505-278 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 FARMINGTON NM
2012-11-16 505-398 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 LAS VEGAS NM
2012-02-17 505-354 0XXX1XXX4XXX5XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 SHIPROCK NM
2011-07-18 505-388 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2010-04-26 505-369 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2008-10-21 505-431 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2008-06-12 505-510 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2008-05-29 505-886 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2008-05-29 505-926 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2004-11-11 505-407 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
2001-08-15 505-715 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
— 505-514 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 ALBUQURQUE NM
— 505-629 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NM 5470 SANTA FE NM

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.