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 405
SOUTHWESTERN BELL 237
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
2015-03-04 405-855 0–9 XXXall 10 · 4 holders which blocks → SOUTHWESTERN BELL 9533 MIDWEST CY OK
2014-10-20 405-252 0–9 XXXall 10 · 5 holders which blocks → SOUTHWESTERN BELL 9533 BRITTON OK
2008-06-19 405-582 0–9 XXXall 10 · 4 holders which blocks → SOUTHWESTERN BELL 9533 MIDWEST CY OK
2008-03-26 405-935 0–9 XXXwhole prefix which blocks → SOUTHWESTERN BELL 9533 BRITTON OK
2008-02-13 405-456 0–9 XXXall 10 · 3 holders which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
2002-06-10 405-587 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
2001-10-05 405-486 0XXX4XXX6XXX7XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 BRITTON OK
2001-09-25 405-487 0XXX6XXX7XXX8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
2001-06-12 405-316 0XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-207 0XXX1XXX3XXX4XXX which blocks → SOUTHWESTERN BELL 9533 PAULS VLY OK
— 405-214 2XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SHAWNEE OK
— 405-216 1XXX3XXX4XXX5XXX6XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 EDMOND OK
— 405-217 0XXX3XXX4XXX5XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 NORMAN OK
— 405-218 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-219 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-222 none assigned yet which blocks → SOUTHWESTERN BELL 9533 CHICKASHA OK
— 405-224 not yet reported which blocks → SOUTHWESTERN BELL 9533 CHICKASHA OK
— 405-228 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-230 0XXX2XXX3XXX4XXX5XXX6XXX7XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-231 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-232 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-234 0XXX1XXX6XXX7XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-235 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-236 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-237 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 MOORE OK
— 405-238 none assigned yet which blocks → SOUTHWESTERN BELL 9533 PAULS VLY OK
— 405-239 0XXX4XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-240 2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 CHANDLER OK
— 405-247 0XXX which blocks → SOUTHWESTERN BELL 9533 ANADARKO OK
— 405-257 0XXX4XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 WEWOKA OK
— 405-258 none assigned yet which blocks → SOUTHWESTERN BELL 9533 CHANDLER OK
— 405-260 2XXX5XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 GUTHRIE OK
— 405-262 not yet reported which blocks → SOUTHWESTERN BELL 9533 EL RENO OK
— 405-264 3XXX6XXX7XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-270 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-271 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-272 not yet reported which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-273 not yet reported which blocks → SOUTHWESTERN BELL 9533 SHAWNEE OK
— 405-275 not yet reported which blocks → SOUTHWESTERN BELL 9533 SHAWNEE OK
— 405-277 0XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 LUTHER OK
— 405-278 1XXX which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-280 3XXX which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-282 not yet reported which blocks → SOUTHWESTERN BELL 9533 GUTHRIE OK
— 405-290 8XXX which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-291 0XXX which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-292 4XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 NORMAN OK
— 405-297 4XXX which blocks → SOUTHWESTERN BELL 9533 OKLA CITY OK
— 405-302 8XXX which blocks → SOUTHWESTERN BELL 9533 BRITTON OK
— 405-303 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 SEMINOLE OK
— 405-307 not yet reported which blocks → SOUTHWESTERN BELL 9533 NORMAN OK

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.