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 580
SOUTHWESTERN BELL 157
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
— 580-337 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 BESSIE OK
— 580-345 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 SOPER OK
— 580-351 2XXX which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-353 9XXX which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-354 2XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-355 not yet reported which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-357 not yet reported which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-362 0XXX4XXX6XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 NEWKIRK OK
— 580-363 not yet reported which blocks → SOUTHWESTERN BELL 9533 BLACKWELL OK
— 580-364 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 ATOKA OK
— 580-367 3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 CADDO OK
— 580-369 4XXX which blocks → SOUTHWESTERN BELL 9533 DAVIS OK
— 580-371 7XXX8XXX which blocks → SOUTHWESTERN BELL 9533 TISHOMINGO OK
— 580-379 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 ALTUS OK
— 580-395 0XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 MEDFORD OK
— 580-421 none assigned yet which blocks → SOUTHWESTERN BELL 9533 ADA OK
— 580-429 4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 CACHE OK
— 580-430 0XXX which blocks → SOUTHWESTERN BELL 9533 ALVA OK
— 580-436 not yet reported which blocks → SOUTHWESTERN BELL 9533 ADA OK
— 580-442 not yet reported which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-446 2XXX3XXX6XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 BRECKENRDG OK
— 580-448 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 SARKNSASCY OK
— 580-456 0XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 ROFF OK
— 580-458 0XXX1XXX2XXX3XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-460 not yet reported which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-470 6XXX which blocks → SOUTHWESTERN BELL 9533 DUNCAN OK
— 580-475 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 DUNCAN OK
— 580-476 0XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 RUSH SPG OK
— 580-477 not yet reported which blocks → SOUTHWESTERN BELL 9533 ALTUS OK
— 580-480 2XXX which blocks → SOUTHWESTERN BELL 9533 ALTUS OK
— 580-481 none assigned yet which blocks → SOUTHWESTERN BELL 9533 ALTUS OK
— 580-482 9XXX which blocks → SOUTHWESTERN BELL 9533 ALTUS OK
— 580-483 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-490 2XXX4XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 ARDMORE OK
— 580-510 9XXX which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-531 not yet reported which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-535 0XXX2XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 GRANITE OK
— 580-536 not yet reported which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-540 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 ENID OK
— 580-547 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 CLINTON OK
— 580-548 none assigned yet which blocks → SOUTHWESTERN BELL 9533 ENID OK
— 580-563 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 BLAIR OK
— 580-564 6XXX which blocks → SOUTHWESTERN BELL 9533 KINGSTON OK
— 580-566 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 BOSWELL OK
— 580-571 none assigned yet which blocks → SOUTHWESTERN BELL 9533 WOODWARD OK
— 580-572 0XXX1XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 PERRY OK
— 580-581 9XXX which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-585 8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-587 5XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 RATTAN OK
— 580-589 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 SO COLDWTR 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.