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 206
LEVEL 3 COMMUNICATIONS, LLC - WA 34
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
2019-11-04 206-580 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2019-04-22 206-688 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2019-02-12 206-584 0–9 XXXall 10 · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2018-04-23 206-531 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2017-10-24 206-702 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2017-06-09 206-480 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2016-08-18 206-646 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2016-08-18 206-773 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2013-05-09 206-602 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2011-06-08 206-512 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2008-05-15 206-452 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2007-08-15 206-455 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2004-09-01 206-259 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 VASHON WA
2002-08-23 206-274 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2001-04-23 206-266 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-219 none assigned yet which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-225 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-330 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-347 2XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 BAINBDG IS WA
— 206-384 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-456 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-508 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-569 4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 RICHMNDBCH WA
— 206-577 none assigned yet which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-653 4XXX5XXX6XXX7XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 DES MOINES WA
— 206-673 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-686 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-734 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-740 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-765 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-774 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-866 1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 BAINBDG IS WA
— 206-922 0XXX2XXX3XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
— 206-934 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA

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.