NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 125
T-MOBILE USA, INC. 79
NEW CINGULAR WIRELESS PCS, LLC - IL 55
LEVEL 3 COMMUNICATIONS, LLC - OH 39
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
— 513-821 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-825 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-826 not yet reported which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 CINCINNATI OH
— 513-827 3XXX6XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 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
— 513-833 0XXX1XXX3XXX4XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 LTL MIAMI OH
— 513-836 1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → T-MOBILE USA, INC. 6529 LEBANON OH
— 513-839 2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → METROPCS, INC. 5562 OXFORD OH
— 513-841 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-842 not yet reported which blocks → PAETEC ITEL, LLC 829J CINCINNATI OH
— 513-843 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 CLERMONT OH
— 513-844 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-845 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 HARRISON OH
— 513-847 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 BETHANY OH
— 513-850 0XXX2XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 LEBANON 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
— 513-855 0–9 XXXall 10 · 4 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K WAYNESVL 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
— 513-875 0XXX1XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LITTLE MIAMI COMMUNICATIONS, CORP. 0613 FAYETTEVL OH
— 513-876 5XXX6XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - OH 0615 FELICITY OH
— 513-877 0XXX1XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LITTLE MIAMI COMMUNICATIONS, CORP. 0613 BUTLERVL OH
— 513-881 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-884 not yet reported which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-885 not yet reported which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-886 not yet reported which blocks → T-MOBILE USA, INC. 6529 CINCINNATI 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
— 513-890 not yet reported which blocks → SPOK, INC. 6630 MIDDLETOWN 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
— 513-897 8XXX which blocks → BRIGHTSPEED OF NORTHWEST OHIO, INC. 0661 WAYNESVL OH

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.