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
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 513-264 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-265 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-266 9XXX which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-267 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 MIDDLETOWN OH
— 513-268 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 SO LEBANON OH
— 513-269 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-271 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-272 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-273 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 OXFORD OH
— 513-274 0XXX2XXX3XXX4XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 LTL MIAMI OH
— 513-275 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 HAMILTON OH
— 513-276 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 CINCINNATI OH
— 513-277 0XXX1XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-278 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 BETHEL OH
— 513-279 2XXX3XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 HARRISON OH
— 513-281 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-284 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-285 2XXX3XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 HAMILTON OH
— 513-286 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 CLERMONT OH
— 513-287 0XXX9XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-288 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-289 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-290 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-293 not yet reported which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-294 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 NEWTONSVL OH
— 513-295 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-296 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 REILY OH
— 513-297 8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 CINCINNATI OH
— 513-298 0XXX2XXX3XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 BETHANY OH
— 513-299 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 SEVEN MILE OH
— 513-300 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-303 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-304 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-305 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-307 not yet reported which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-308 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 CINCINNATI OH
— 513-309 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-310 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX OH
— 513-312 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-313 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-314 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-315 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-316 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-317 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-319 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
— 513-320 7XXX8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 MIDDLETOWN OH
— 513-321 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-323 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 SHANDON OH
— 513-324 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI 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.