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
2008-01-21 513-834 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2008-01-16 513-442 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - OH 464C CINCINNATI OH
2007-10-31 513-862 0–9 XXXwhole prefix which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2007-10-31 513-865 0–9 XXXwhole prefix which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2007-10-30 513-372 0–9 XXXall 10 · 4 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2007-10-17 513-206 0–9 XXXall 10 · 4 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2007-10-16 513-628 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2007-08-29 513-432 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2007-08-08 513-824 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2007-07-25 513-429 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2007-05-23 513-578 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2007-03-28 513-428 0–9 XXXall 10 · 5 holders which blocks → CINCINNATI BELL EXTENDED TERRITORIES LLC - OH 309B TRENTON OH
2007-03-27 513-693 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2007-02-16 513-468 0–9 XXXall 10 · 7 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K TRENTON OH
2007-02-02 513-485 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2006-12-14 513-746 0–9 XXXall 10 · 2 holders which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 CINCINNATI OH
2006-08-21 513-878 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 CINCINNATI OH
2006-07-05 513-803 0–9 XXXwhole prefix which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2006-04-26 513-488 0–9 XXXall 10 · 3 holders which blocks → PAETEC ITEL, LLC 829J CINCINNATI OH
2006-04-19 513-393 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MIDDLETOWN OH
2006-04-13 513-668 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HAMILTON OH
2006-04-13 513-767 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NEWTONSVL OH
2006-03-03 513-344 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2005-12-22 513-445 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 MASON OH
2005-08-19 513-386 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - OH 464C CINCINNATI OH
2004-06-23 513-291 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 SEVEN MILE OH
2003-12-09 513-204 0–9 XXXall 10 · 2 holders which blocks → CINCINNATI BELL EXTENDED TERRITORIES LLC - OH 309B MASON OH
2003-10-30 513-217 0–9 XXXall 10 · 3 holders which blocks → CINCINNATI BELL EXTENDED TERRITORIES LLC - OH 309B MIDDLETOWN OH
2003-10-30 513-360 0–9 XXXall 10 · 8 holders which blocks → CINCINNATI BELL EXTENDED TERRITORIES LLC - OH 309B MONROE OH
2003-06-20 513-322 0–9 XXXall 10 · 4 holders which blocks → CITYNET OHIO, LLC - OH 036B CINCINNATI OH
2002-10-22 513-363 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2002-09-17 513-359 not yet reported which blocks → SPOK, INC. 6630 CINCINNATI OH
2002-08-27 513-318 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 MIDDLETOWN OH
2002-04-23 513-341 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 HAMILTON OH
2002-04-09 513-331 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 LEBANON OH
2002-04-03 513-795 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 HAMILTON OH
2002-03-27 513-334 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 LTL MIAMI OH
2002-03-21 513-392 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 MIDDLETOWN OH
2002-03-15 513-283 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2002-03-04 513-292 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 MIDDLETOWN OH
2001-12-20 513-261 7XXX8XXX9XXX which blocks → LEVEL 3 TELECOM OF OHIO, LLC - OH 7460 MIDDLETOWN OH
2001-11-28 513-282 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 LEBANON OH
2001-11-14 513-907 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 HAMILTON OH
2001-10-09 513-600 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 LTL MIAMI OH
2001-08-30 513-280 4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 OXFORD OH
2001-05-31 513-898 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 CINCINNATI OH
2001-05-24 513-534 not yet reported which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2001-04-30 513-849 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 MIDDLETOWN OH
2001-03-06 513-678 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2001-03-06 513-830 3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 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.