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
2012-01-31 513-516 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2012-01-31 513-601 0–9 XXXall 10 · 3 holders which blocks → CINCINNATI BELL 9348 CINCINNATI OH
2012-01-10 513-512 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 CINCINNATI OH
2011-12-21 513-510 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-12-21 513-580 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-11-30 513-507 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2011-11-16 513-413 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-10-06 513-212 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2011-09-20 513-302 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-09-20 513-501 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-09-13 513-882 0–9 XXXall 10 · 4 holders which blocks → CITYNET OHIO, LLC - OH 036B CINCINNATI OH
2011-09-07 513-441 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2011-08-11 513-415 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2011-08-08 513-431 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2011-08-04 513-394 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-08-04 513-399 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-07-15 513-391 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2011-07-05 513-462 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-06-13 513-384 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2011-06-02 513-370 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 CINCINNATI OH
2011-05-27 513-306 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-05-27 513-356 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-05-17 513-222 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2011-03-17 513-635 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2011-03-16 513-301 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-03-11 513-214 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - OH 4863 CINCINNATI OH
2011-02-25 513-568 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-02-23 513-888 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2011-02-09 513-900 0–9 XXXall 10 · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 LTL MIAMI OH
2011-01-12 513-800 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2011-01-03 513-500 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2010-12-15 513-400 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2010-11-08 513-430 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2010-09-08 513-439 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2010-06-08 513-446 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2010-05-06 513-409 0–9 XXXall 10 · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 LEBANON OH
2010-03-18 513-426 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2010-01-26 513-402 0–9 XXXall 10 · 8 holders which blocks → PAETEC ITEL, LLC 829J MONROE OH
2009-10-14 513-448 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2009-10-09 513-208 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2009-10-09 513-223 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2009-10-09 513-250 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2009-10-06 513-835 0–9 XXXall 10 · 4 holders which blocks → CINBELL EXT TERR LLC DBA ALTAFIBER CONNECTED SVCS 600F CINCINNATI OH
2009-09-22 513-655 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2009-04-22 513-828 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2009-02-09 513-692 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2008-10-08 513-823 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2008-07-03 513-748 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2008-06-19 513-846 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 CINCINNATI OH
2008-05-13 513-549 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - OH 001F 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.