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 918
SOUTHWESTERN BELL 236
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
2006-08-09 918-444 0–9 XXXwhole prefix which blocks → SOUTHWESTERN BELL 9533 TAHLEQUAH OK
2001-09-25 918-502 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
2001-08-20 918-348 0XXX1XXX2XXX4XXX5XXX6XXX8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 MUSKOGEE OK
2001-06-13 918-713 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 VINITA OK
2001-06-13 918-719 1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 COPAN OK
2001-05-07 918-708 1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 TAHLEQUAH OK
2001-05-07 918-715 1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 MCALESTER OK
2001-05-07 918-725 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 CUSHING OK
2001-04-12 918-403 8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-204 1XXX2XXX3XXX4XXX8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-207 2XXX5XXX6XXX7XXX8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 TAHLEQUAH OK
— 918-223 1XXX3XXX4XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 CUSHING OK
— 918-224 not yet reported which blocks → SOUTHWESTERN BELL 9533 SAPULPA OK
— 918-225 not yet reported which blocks → SOUTHWESTERN BELL 9533 CUSHING OK
— 918-227 not yet reported which blocks → SOUTHWESTERN BELL 9533 SAPULPA OK
— 918-233 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 SO CHETOPA OK
— 918-234 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-235 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 SALLISAW OK
— 918-237 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-241 not yet reported which blocks → SOUTHWESTERN BELL 9533 SAND SPG OK
— 918-245 not yet reported which blocks → SOUTHWESTERN BELL 9533 SAND SPG OK
— 918-246 5XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 SAND SPG OK
— 918-248 0XXX1XXX2XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 SAPULPA OK
— 918-255 0XXX1XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 SOCOFFEYVL OK
— 918-256 not yet reported which blocks → SOUTHWESTERN BELL 9533 VINITA OK
— 918-257 0XXX3XXX6XXX7XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 AFTON OK
— 918-266 not yet reported which blocks → SOUTHWESTERN BELL 9533 CATOOSA OK
— 918-270 0XXX3XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-272 not yet reported which blocks → SOUTHWESTERN BELL 9533 OWASSO OK
— 918-273 6XXX which blocks → SOUTHWESTERN BELL 9533 NOWATA OK
— 918-274 not yet reported which blocks → SOUTHWESTERN BELL 9533 OWASSO OK
— 918-280 0XXX1XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-283 0XXX3XXX4XXX5XXX6XXX7XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 CLAREMORE OK
— 918-285 2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 CUSHING OK
— 918-287 6XXX8XXX which blocks → SOUTHWESTERN BELL 9533 PAWHUSKA OK
— 918-288 0XXX2XXX3XXX5XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 SPERRY OK
— 918-291 0XXX1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 JENKS OK
— 918-292 8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-293 8XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-295 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-296 4XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 JENKS OK
— 918-297 0XXX4XXX6XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 HARTSHORNE OK
— 918-298 9XXX which blocks → SOUTHWESTERN BELL 9533 JENKS OK
— 918-299 not yet reported which blocks → SOUTHWESTERN BELL 9533 JENKS OK
— 918-302 1XXX2XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 MCALESTER OK
— 918-304 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 OKMULGEE OK
— 918-321 0XXX2XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 KIEFER OK
— 918-322 0XXX1XXX2XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 KIEFER OK
— 918-323 1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 VINITA OK
— 918-324 0XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 DEPEW 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.