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
QWEST CORPORATION 243
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
2017-06-13 206-231 0–9 XXXall 10 · 6 holders which blocks → QWEST CORPORATION 9638 DES MOINES WA
2016-05-05 206-481 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SEATTLE WA
2015-08-20 206-630 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SEATTLE WA
2014-04-04 206-597 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SEATTLE WA
2012-03-19 206-477 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SEATTLE WA
2008-11-06 206-787 0–9 XXXall 10 · 4 holders which blocks → QWEST CORPORATION 9638 SEATTLE WA
2007-03-29 206-884 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SEATTLE WA
2001-06-06 206-987 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-205 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-213 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-214 5XXX6XXX7XXX8XXX which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-215 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-216 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-217 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-218 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-220 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-221 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-223 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-224 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-230 1XXX2XXX3XXX · 2 holders which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-232 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-233 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-236 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-239 8XXX which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-241 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-242 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-243 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-244 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-246 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-248 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-254 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-256 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-262 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-263 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-264 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-265 0XXX1XXX2XXX3XXX9XXX which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-269 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-270 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-272 0XXX which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-273 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-275 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-277 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-281 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-282 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-283 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-284 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-285 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-286 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-287 not yet reported which blocks → QWEST CORPORATION 9638 SEATTLE WA
— 206-292 not yet reported which blocks → QWEST CORPORATION 9638 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.