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
2024-02-02 513-329 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 CINCINNATI OH
2023-06-09 513-606 0XXX1XXX2XXX3XXX8XXX9XXX · 5 holders which blocks → ONVOY, LLC - OH 464C MONROE OH
2023-06-09 513-927 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - OH 464C MIDDLETOWN OH
2023-05-15 513-775 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - OH 464C BETHANY OH
2023-05-15 513-776 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - OH 464C CINCINNATI OH
2023-05-09 513-747 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 HAMILTON OH
2023-04-11 513-380 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY SPECTRUM, LLC 624H FELICITY OH
2023-03-29 513-656 0–9 XXXall 10 · 5 holders which blocks → BOOST SUBSCRIBERCO L.L.C. 490J CINCINNATI OH
2023-03-20 513-962 0–9 XXXall 10 · 5 holders which blocks → AT&T - LOCAL 7421 NEWTONSVL OH
2023-03-10 513-220 0–9 XXXall 10 · 3 holders which blocks → SKYE TELECOM LLC DBA SKYETEL 622J CINCINNATI OH
2023-03-01 513-994 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - OH 464C MASON OH
2023-02-28 513-992 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - OH 464C LTL MIAMI OH
2023-02-08 513-513 0–9 XXXwhole prefix which blocks → ONVOY, LLC - OH 464C CINCINNATI OH
2023-02-08 513-990 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 HAMILTON OH
2023-01-11 513-650 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 MIDDLETOWN OH
2023-01-11 513-980 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 OXFORD OH
2022-12-08 513-610 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 SEVEN MILE OH
2022-12-08 513-859 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CINCINNATI OH
2022-12-08 513-930 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - OH 001F CINCINNATI OH
2022-12-08 513-937 0–9 XXXwhole prefix which blocks → ONVOY, LLC - OH 464C CINCINNATI OH
2022-11-08 513-637 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - OH 464C MASON OH
2022-11-08 513-938 0–9 XXXwhole prefix which blocks → ONVOY, LLC - OH 464C CINCINNATI OH
2022-09-09 513-740 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - OH 464C HAMILTON OH
2022-08-09 513-840 0–9 XXXwhole prefix which blocks → ONVOY, LLC - OH 464C CINCINNATI OH
2022-07-12 513-224 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LEBANON OH
2022-06-08 513-957 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SEVEN MILE OH
2022-06-08 513-960 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 HAMILTON OH
2022-05-09 513-955 0–9 XXXall 10 · 4 holders which blocks → BARR TELL USA 907J CINCINNATI OH
2022-04-08 513-998 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OH 6025 LTL MIAMI OH
2022-03-09 513-963 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MIDDLETOWN OH
2022-01-11 513-450 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - OH 464C OXFORD OH
2021-12-08 513-949 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - OH 7532 WAYNESVL OH
2021-11-09 513-935 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - OH 001F BETHANY OH
2021-09-09 513-902 0–9 XXXall 10 · 4 holders which blocks → TELNYX LLC 073H CLERMONT OH
2021-09-08 513-879 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2021-04-29 513-848 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - OH 464C MASON OH
2021-04-13 513-838 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2021-04-08 513-905 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - OH 001F HAMILTON OH
2021-04-01 513-764 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 CINCINNATI OH
2021-02-09 513-837 0–9 XXXall 10 · 4 holders which blocks → TON80 COMMUNICATIONS, LLC 516J CINCINNATI OH
2021-01-27 513-809 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 LEBANON OH
2021-01-27 513-822 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 MIDDLETOWN OH
2020-12-21 513-790 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - OH 464C HAMILTON OH
2020-11-18 513-653 0–9 XXXall 10 · 3 holders which blocks → TWILIO INTERNATIONAL, INC. 506J CINCINNATI OH
2020-10-13 513-778 0–9 XXXall 10 · 3 holders which blocks → NUSO, LLC 478J CINCINNATI OH
2020-09-25 513-743 0–9 XXXall 10 · 6 holders which blocks → IP HORIZON LLC 515J CINCINNATI OH
2020-08-14 513-750 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - OH 001F CLERMONT OH
2020-08-07 513-694 0–9 XXXall 10 · 2 holders which blocks → CSC WIRELESS, LLC 425J CINCINNATI OH
2020-07-17 513-690 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 SEVEN MILE OH
2020-07-16 513-991 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - OH 464C 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.