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 501
SOUTHWESTERN BELL 165
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
— 501-354 not yet reported which blocks → SOUTHWESTERN BELL 9533 MORRILTON AR
— 501-362 not yet reported which blocks → SOUTHWESTERN BELL 9533 HEBER SPG AR
— 501-368 5XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SEARCY AR
— 501-370 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-371 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-372 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-373 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-374 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-375 none assigned yet which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-376 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-377 9XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-378 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-379 0XXX6XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-380 0–9 XXXall 10 · 5 holders which blocks → SOUTHWESTERN BELL 9533 SEARCY AR
— 501-396 6XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-399 4XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-407 1XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-433 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-450 not yet reported which blocks → SOUTHWESTERN BELL 9533 CONWAY AR
— 501-455 9XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-467 1XXX2XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 MALVERN AR
— 501-470 5XXX6XXX7XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 CONWAY AR
— 501-477 0XXX1XXX3XXX4XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 MORRILTON AR
— 501-490 9XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-504 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 CONWAY AR
— 501-505 0XXX4XXX6XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 CONWAY AR
— 501-513 7XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 CONWAY AR
— 501-515 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-520 1XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-525 not yet reported which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-557 0XXX3XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 BAUXITE AR
— 501-558 7XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-562 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-565 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-568 8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-569 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-570 6XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-594 0XXX2XXX3XXX4XXX6XXX7XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 PARON AR
— 501-602 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 BAUXITE AR
— 501-603 none assigned yet which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-609 not yet reported which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-614 0XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-615 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-618 0XXX1XXX5XXX6XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-620 none assigned yet which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-622 not yet reported which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-623 not yet reported which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-624 not yet reported which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-625 0XXX1XXX2XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-627 not yet reported which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR

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.