NumberResearch Membership · Data 09/21/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/21/2026

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 312
SPOK, INC. 33
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
— 312-249 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-250 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-271 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-272 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-289 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-290 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-295 not yet reported which blocks → SPOK, INC. 6630 LA GRANGE IL
— 312-299 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-349 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-359 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-365 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-367 not yet reported which blocks → SPOK, INC. 6630 LA GRANGE IL
— 312-370 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-378 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-387 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-389 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-398 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-418 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-484 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-490 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-495 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-512 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-562 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-571 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-657 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-677 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-688 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-717 not yet reported which blocks → SPOK, INC. 6630 LA GRANGE IL
— 312-851 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-891 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-901 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-941 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL
— 312-963 not yet reported which blocks → SPOK, INC. 6630 CHICGOZN01 IL

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/21/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.