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 513
CINCINNATI BELL 251
CINCINNATI BELL EXTENDED TERRITORIES LLC - OH 9
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
— 513-793 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-794 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-797 not yet reported which blocks → CINCINNATI BELL 9348 CLERMONT OH
— 513-820 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-821 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-825 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-829 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-831 not yet reported which blocks → CINCINNATI BELL 9348 LTL MIAMI OH
— 513-841 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-844 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-851 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-852 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-853 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-856 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-858 0XXX5XXX9XXX · 2 holders which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-860 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-861 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-863 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-864 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-867 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-868 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-869 0XXX1XXX3XXX6XXX8XXX9XXX · 3 holders which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-870 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-871 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-872 9XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-874 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-881 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-887 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-889 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-891 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-892 9XXX which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-893 6XXX7XXX9XXX · 3 holders which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-894 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-895 9XXX which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-896 0XXX which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-921 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-922 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-923 0XXX6XXX7XXX8XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-924 3XXX4XXX6XXX7XXX · 2 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-925 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-929 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-931 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-936 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-939 4XXX5XXX6XXX7XXX8XXX9XXX which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-941 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-942 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-943 not yet reported which blocks → CINCINNATI BELL 9348 CLERMONT OH
— 513-945 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-946 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-947 not yet reported which blocks → CINCINNATI BELL 9348 CLERMONT OH

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.