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 509
QWEST CORPORATION 132
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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2011-10-19 509-724 0–9 XXXall 10 · 4 holders which blocks → QWEST CORPORATION 9638 SPOKANE WA
2010-06-04 509-828 0–9 XXXall 10 · 4 holders which blocks → QWEST CORPORATION 9638 SPOKANE WA
2008-03-27 509-313 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-225 0XXX9XXX · 2 holders which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-226 none assigned yet which blocks → QWEST CORPORATION 9638 NEWMANLAKE WA
— 509-227 9XXX which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-228 1XXX2XXX3XXX7XXX8XXX · 3 holders which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-233 4XXX5XXX6XXX7XXX · 4 holders which blocks → QWEST CORPORATION 9638 LOON LAKE WA
— 509-238 7XXX8XXX · 2 holders which blocks → QWEST CORPORATION 9638 ELK-GRNBLF WA
— 509-244 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-248 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-249 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-255 2XXX3XXX4XXX7XXX8XXX · 4 holders which blocks → QWEST CORPORATION 9638 LIBERTY LK WA
— 509-258 2XXX3XXX5XXX · 3 holders which blocks → QWEST CORPORATION 9638 SPRINGDALE WA
— 509-262 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → QWEST CORPORATION 9638 DEER PARK WA
— 509-276 0XXX which blocks → QWEST CORPORATION 9638 DEER PARK WA
— 509-292 4XXX6XXX · 2 holders which blocks → QWEST CORPORATION 9638 ELK-GRNBLF WA
— 509-323 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-324 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-325 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-326 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-327 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-328 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-329 6XXX8XXX · 2 holders which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-331 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9638 OTHELLO WA
— 509-337 2XXX3XXX4XXX5XXX · 4 holders which blocks → QWEST CORPORATION 9638 WAITSBURG WA
— 509-349 3XXX4XXX5XXX6XXX · 4 holders which blocks → QWEST CORPORATION 9638 WARDEN WA
— 509-353 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-354 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-358 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-363 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-368 0XXX1XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-382 5XXX6XXX7XXX · 3 holders which blocks → QWEST CORPORATION 9638 DAYTON WA
— 509-394 4XXX5XXX7XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9638 TOUCHET WA
— 509-397 7XXX8XXX which blocks → QWEST CORPORATION 9638 COLFAX WA
— 509-422 not yet reported which blocks → QWEST CORPORATION 9638 OMAK WA
— 509-441 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-443 3XXX4XXX5XXX which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-448 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-451 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-452 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-453 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-454 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-455 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-456 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-457 not yet reported which blocks → QWEST CORPORATION 9638 YAKIMA WA
— 509-458 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-459 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-464 6XXX7XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9638 SPOKANE WA
— 509-465 not yet reported which blocks → QWEST CORPORATION 9638 SPOKANE 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.