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
— 513-200 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-201 3XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J CLERMONT OH
— 513-202 2XXX3XXX4XXX6XXX · 2 holders which blocks → CINCINNATI BELL 9348 HARRISON OH
— 513-203 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-205 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-207 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-209 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-210 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-211 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX OH
— 513-213 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-218 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-219 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 CINCINNATI OH
— 513-221 9XXX which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-225 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-226 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-227 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-228 not yet reported which blocks → CINCINNATI BELL EXTENDED TERRITORIES LLC - OH 309B LEBANON OH
— 513-229 9XXX which blocks → CINCINNATI BELL EXTENDED TERRITORIES LLC - OH 309B MASON OH
— 513-230 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-231 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-232 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-233 1XXX5XXX7XXX8XXX · 3 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-234 0XXX1XXX2XXX3XXX4XXX5XXX7XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 MASON OH
— 513-235 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-236 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-237 not yet reported which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-238 not yet reported which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-239 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - OH 7836 LTL MIAMI OH
— 513-240 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-241 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-242 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-243 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-244 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-245 4XXX8XXX · 2 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-246 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-247 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-248 not yet reported which blocks → CINCINNATI BELL 9348 LTL MIAMI OH
— 513-249 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
— 513-251 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
— 513-252 0XXX2XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-253 0XXX which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-254 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-255 9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 OXFORD OH
— 513-256 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-257 0XXX2XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-258 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-259 0XXX2XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
— 513-260 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-262 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
— 513-263 0XXX 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.