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 561
SPOK, INC. 16
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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 561-224 not yet reported which blocks → SPOK, INC. 6630 BOYNTONBCH FL
— 561-230 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-326 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-387 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-551 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-553 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-554 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-604 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-610 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-751 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-754 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-773 not yet reported which blocks → SPOK, INC. 6630 BOCA RATON FL
— 561-874 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-885 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-936 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL
— 561-937 not yet reported which blocks → SPOK, INC. 6630 WPALMBEACH FL

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.