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 253
QWEST CORPORATION 141
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
2012-06-07 253-545 0–9 XXXall 10 · 4 holders which blocks → QWEST CORPORATION 9638 AUBURN WA
2002-12-17 253-944 1XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9638 TACOMAWVLY WA
2002-08-26 253-928 not yet reported which blocks → QWEST CORPORATION 9638 TACOMAWVLY WA
2001-04-23 253-966 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
2001-04-23 253-967 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
2001-04-23 253-968 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-207 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-272 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-274 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-280 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-288 not yet reported which blocks → QWEST CORPORATION 9638 AUBURN WA
— 253-305 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-333 not yet reported which blocks → QWEST CORPORATION 9638 AUBURN WA
— 253-351 not yet reported which blocks → QWEST CORPORATION 9638 AUBURN WA
— 253-372 2XXX8XXX which blocks → QWEST CORPORATION 9638 KENT WA
— 253-373 8XXX which blocks → QWEST CORPORATION 9638 KENT WA
— 253-382 5XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-383 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-395 not yet reported which blocks → QWEST CORPORATION 9638 KENT WA
— 253-396 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-403 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-404 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-426 0XXX1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-428 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-435 not yet reported which blocks → QWEST CORPORATION 9638 PUYALLUP WA
— 253-437 not yet reported which blocks → QWEST CORPORATION 9638 KENT WA
— 253-445 not yet reported which blocks → QWEST CORPORATION 9638 PUYALLUP WA
— 253-446 2XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → QWEST CORPORATION 9638 PUYALLUP WA
— 253-459 0XXX2XXX3XXX4XXX5XXX9XXX which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-460 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-471 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-472 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-473 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-474 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-475 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-476 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-477 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-487 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → QWEST CORPORATION 9638 KENT WA
— 253-502 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-512 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-520 not yet reported which blocks → QWEST CORPORATION 9638 KENT WA
— 253-528 3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → QWEST CORPORATION 9638 DES MOINES WA
— 253-529 not yet reported which blocks → QWEST CORPORATION 9638 DES MOINES WA
— 253-531 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-534 5XXX6XXX8XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-535 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-536 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-537 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-538 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA WA
— 253-539 not yet reported which blocks → QWEST CORPORATION 9638 TACOMA 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.