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
— 513-683 not yet reported which blocks → CINCINNATI BELL 9348 LTL MIAMI OH
— 513-684 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-685 0XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 CLERMONT OH
— 513-686 0XXX9XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-687 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-688 not yet reported which blocks → CINCINNATI BELL 9348 CLERMONT OH
— 513-691 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-695 not yet reported which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 LEBANON OH
— 513-696 2XXX6XXX7XXX9XXX · 3 holders which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 LEBANON OH
— 513-697 not yet reported which blocks → CINCINNATI BELL 9348 LTL MIAMI OH
— 513-698 2XXX5XXX8XXX · 2 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-699 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 CINCINNATI OH
— 513-700 not yet reported which blocks → OH
— 513-701 8XXX9XXX · 2 holders which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 MASON OH
— 513-702 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-703 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-705 3XXX which blocks → OHIO BELL TEL CO 9321 MIDDLETOWN OH
— 513-706 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-707 2XXX8XXX which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 LTL MIAMI OH
— 513-708 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-709 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-710 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX OH
— 513-712 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 BETHANY OH
— 513-714 2XXX3XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 HAMILTON OH
— 513-715 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - OH 464C HARRISON OH
— 513-716 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 LTL MIAMI OH
— 513-717 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 SHANDON OH
— 513-718 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 CLERMONT OH
— 513-719 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 CINCINNATI OH
— 513-720 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-721 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-722 5XXX6XXX which blocks → CINCINNATI BELL 9348 LTL MIAMI OH
— 513-723 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-724 4XXX which blocks → CINCINNATI BELL 9348 WILLIAMSBG OH
— 513-726 2XXX3XXX7XXX8XXX9XXX · 5 holders which blocks → CINCINNATI BELL 9348 SEVEN MILE OH
— 513-727 not yet reported which blocks → OHIO BELL TEL CO 9321 MIDDLETOWN OH
— 513-728 0XXX1XXX5XXX9XXX · 2 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-729 6XXX7XXX9XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-730 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 CINCINNATI OH
— 513-731 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-732 not yet reported which blocks → CINCINNATI BELL 9348 CLERMONT OH
— 513-733 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-734 5XXX8XXX · 2 holders which blocks → CINCINNATI BELL 9348 BETHEL OH
— 513-735 not yet reported which blocks → CINCINNATI BELL 9348 CLERMONT OH
— 513-736 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-737 not yet reported which blocks → CINCINNATI BELL 9348 HAMILTON OH
— 513-738 6XXX which blocks → CINCINNATI BELL 9348 SHANDON OH
— 513-739 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-741 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI 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.