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 253
LEVEL 3 COMMUNICATIONS, LLC - WA 29
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
2019-01-29 253-393 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
2012-01-09 253-442 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
2002-12-10 253-200 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 PUYALLUP WA
2002-08-27 253-235 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMAWVLY WA
2002-08-27 253-236 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 KENT WA
2002-03-12 253-336 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 DES MOINES WA
2002-02-21 253-655 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 GRAHAM WA
2002-02-21 253-656 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 KENT WA
— 253-205 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 AUBURN WA
— 253-210 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 GRAHAM WA
— 253-231 0XXX1XXX2XXX3XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMAWVLY WA
— 253-238 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
— 253-239 0XXX2XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 KENT WA
— 253-269 2XXX7XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 AUBURN WA
— 253-275 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 AUBURN WA
— 253-321 0XXX1XXX2XXX3XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SUMNER WA
— 253-444 7XXX8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
— 253-449 1XXX3XXX6XXX7XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 DES MOINES WA
— 253-458 5XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 KENT WA
— 253-466 3XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 PUYALLUP WA
— 253-499 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 KENT WA
— 253-501 0XXX1XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SUMNER WA
— 253-590 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
— 253-617 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
— 253-642 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 DES MOINES WA
— 253-666 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
— 253-777 2XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
— 253-948 2XXX6XXX7XXX8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMA WA
— 253-954 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 TACOMAWVLY WA

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.