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
— 918-477 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-478 0XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 FORTGIBSON OK
— 918-481 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-487 0XXX3XXX6XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 BRAGGS OK
— 918-488 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-491 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-492 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-493 0XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-494 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-495 4XXX5XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-496 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-497 0XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-498 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 WUNIONTOWN OK
— 918-499 0XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-523 0XXX4XXX7XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-524 2XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-532 3XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 COPAN OK
— 918-534 8XXX which blocks → SOUTHWESTERN BELL 9533 DEWEY OK
— 918-540 8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 MIAMI OK
— 918-541 3XXX4XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 MIAMI OK
— 918-542 none assigned yet which blocks → SOUTHWESTERN BELL 9533 MIAMI OK
— 918-544 2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 MIAMI OK
— 918-549 0XXX1XXX5XXX8XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-551 1XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-560 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-561 6XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-567 1XXX5XXX6XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 TALIHINA OK
— 918-573 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-574 1XXX2XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-576 1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-579 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-581 3XXX4XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-582 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-583 8XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-584 8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-585 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-586 2XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-587 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-588 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-591 2XXX3XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-592 8XXX which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-594 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-595 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-596 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-599 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-610 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-618 0XXX1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 EUFAULA OK
— 918-619 2XXX3XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-621 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA OK
— 918-622 not yet reported which blocks → SOUTHWESTERN BELL 9533 TULSA 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.