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 505
QWEST CORPORATION 184
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
2015-11-09 505-337 0–9 XXXall 10 · 8 holders which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2008-09-15 505-697 0–9 XXXall 10 · 2 holders which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2007-06-08 505-383 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2006-08-29 505-283 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2006-04-24 505-999 0–9 XXXall 10 · 4 holders which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2003-07-30 505-606 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9636 LOS ALAMOS NM
2001-05-08 505-232 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-254 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-255 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-256 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-260 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-262 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-265 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-266 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
2001-05-08 505-268 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-222 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-223 none assigned yet which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-224 none assigned yet which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-237 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-241 9XXX which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-242 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-243 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-244 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-245 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-246 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-247 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-248 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-271 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-272 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-275 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-277 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-281 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-282 none assigned yet which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-284 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-285 0XXX1XXX7XXX8XXX · 2 holders which blocks → QWEST CORPORATION 9636 GRANTS NM
— 505-286 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-287 0XXX1XXX · 2 holders which blocks → QWEST CORPORATION 9636 GRANTS NM
— 505-291 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-292 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-293 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-294 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-296 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-298 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-299 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-323 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM
— 505-324 not yet reported which blocks → QWEST CORPORATION 9636 FARMINGTON NM
— 505-325 not yet reported which blocks → QWEST CORPORATION 9636 FARMINGTON NM
— 505-326 not yet reported which blocks → QWEST CORPORATION 9636 FARMINGTON NM
— 505-327 not yet reported which blocks → QWEST CORPORATION 9636 FARMINGTON NM
— 505-332 not yet reported which blocks → QWEST CORPORATION 9636 ALBUQURQUE NM

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.