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 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
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 513-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX OH
— 513-612 0XXX8XXX9XXX · 3 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-614 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-615 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-616 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-617 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-618 not yet reported which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 CINCINNATI OH
— 513-619 0XXX which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 CINCINNATI OH
— 513-621 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-622 9XXX which blocks → BRIGHTSPEED OF NORTHWEST OHIO, INC. 0661 MASON OH
— 513-623 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-624 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-625 not yet reported which blocks → CINCINNATI BELL 9348 NEWTONSVL OH
— 513-626 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-627 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-629 0XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-631 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-632 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-633 7XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-634 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-636 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-638 2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-639 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-641 6XXX7XXX8XXX9XXX · 2 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-642 1XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 HAMILTON OH
— 513-644 0XXX2XXX3XXX5XXX6XXX9XXX · 5 holders which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 BETHANY OH
— 513-645 3XXX6XXX7XXX · 2 holders which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 HAMILTON OH
— 513-646 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-648 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-649 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MIDDLETOWN OH
— 513-651 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-652 4XXX8XXX which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-658 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-659 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-660 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-661 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-662 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-664 0XXX7XXX · 2 holders which blocks → FRONTIER NORTH, INC. - OH 0615 OXFORD OH
— 513-665 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-670 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-671 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-672 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-673 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-674 8XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-675 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-677 not yet reported which blocks → CINCINNATI BELL 9348 LTL MIAMI OH
— 513-679 0XXX1XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-680 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-681 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-682 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH

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.