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 323
PACIFIC BELL 265
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
— 323-299 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 12 CA
— 323-307 1XXX2XXX6XXX7XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 05 CA
— 323-308 0XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-321 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 09 CA
— 323-326 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-340 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-341 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-342 2XXX3XXX5XXX7XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 04 CA
— 323-343 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 04 CA
— 323-344 2XXX6XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-349 none assigned yet which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-352 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → PACIFIC BELL 9740 LSAN DA 04 CA
— 323-357 2XXX4XXX which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-370 0XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-373 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → PACIFIC BELL 9740 LSAN DA 11 CA
— 323-382 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-384 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-415 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 05 CA
— 323-418 2XXX7XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 09 CA
— 323-420 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 09 CA
— 323-421 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → PACIFIC BELL 9740 LSAN DA 12 CA
— 323-436 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-441 3XXX5XXX6XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 04 CA
— 323-460 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-461 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-462 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-463 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-464 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-465 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-466 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-467 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-468 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-469 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-478 none assigned yet which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-512 1XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-520 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 14 CA
— 323-521 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PACIFIC BELL 9740 LSAN DA 08 CA
— 323-525 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-526 8XXX which blocks → PACIFIC BELL 9740 LSAN DA 05 CA
— 323-539 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 04 CA
— 323-541 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → PACIFIC BELL 9740 LSAN DA 09 CA
— 323-545 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → PACIFIC BELL 9740 LSAN DA 12 CA
— 323-549 8XXX which blocks → PACIFIC BELL 9740 LSAN DA 13 CA
— 323-550 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-551 7XXX8XXX9XXX · 2 holders which blocks → PACIFIC BELL 9740 LSAN DA 03 CA
— 323-560 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-562 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-563 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-564 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 06 CA
— 323-565 not yet reported which blocks → PACIFIC BELL 9740 LSAN DA 09 CA

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.