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 323
PACIFIC BELL 265
METROPCS NETWORKS, LLC 85
T-MOBILE USA, INC. 64
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 45
NEW CINGULAR WIRELESS PCS, LLC 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
2025-04-02 323-323 0–9 XXXall 10 · 2 holders which blocks → WIDE VOICE, LLC - CA 252F LSAN DA 09 CA
2024-06-03 323-941 0–9 XXXall 10 · 3 holders which blocks → ONVOY SPECTRUM, LLC 624H LSAN DA 02 CA
2024-04-12 323-824 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 14 CA
2021-09-23 323-659 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 MONTEBELLO CA
2019-03-19 323-949 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 MONTEBELLO CA
2019-01-22 323-760 0–9 XXXall 10 · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7139 LSAN DA 14 CA
2018-10-19 323-970 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 LSAN DA 09 CA
2018-03-23 323-910 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 14 CA
2018-03-13 323-814 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 09 CA
2018-03-13 323-955 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 13 CA
2018-03-13 323-990 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 04 CA
2018-03-09 323-991 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 08 CA
2017-11-27 323-763 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 06 CA
2017-07-19 323-918 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 08 CA
2017-06-27 323-968 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 05 CA
2017-05-22 323-408 0–9 XXXall 10 · 2 holders which blocks → METROPCS NETWORKS, LLC 899D LSAN DA 14 CA
2017-04-07 323-880 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 09 CA
2017-03-29 323-914 0–9 XXXall 10 · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7139 MONTEBELLO CA
2016-11-18 323-853 0–9 XXXall 10 · 7 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F MONTEBELLO CA
2016-11-18 323-996 0–9 XXXall 10 · 5 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F LSAN DA 06 CA
2016-11-11 323-994 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 14 CA
2016-10-18 323-831 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 05 CA
2016-09-30 323-628 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 14 CA
2016-09-26 323-925 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 03 CA
2016-07-22 323-530 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 MONTEBELLO CA
2016-07-18 323-986 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - CA 649C LSAN DA 04 CA
2016-07-15 323-961 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 LSAN DA 09 CA
2016-07-11 323-713 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F LSAN DA 09 CA
2016-06-29 323-917 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 13 CA
2016-06-23 323-607 0–9 XXXwhole prefix which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 06 CA
2016-06-23 323-689 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 08 CA
2016-06-17 323-705 0–9 XXXall 10 · 3 holders which blocks → METROPCS NETWORKS, LLC 899D LSAN DA 02 CA
2016-03-09 323-616 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 03 CA
2015-12-15 323-701 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - CA 649C LSAN DA 14 CA
2015-12-01 323-613 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - CA 649C LSAN DA 03 CA
2015-11-23 323-310 0–9 XXXwhole prefix which blocks → ONVOY, LLC - CA 649C LSAN DA 06 CA
2015-11-17 323-716 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 11 CA
2015-09-22 323-612 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 04 CA
2015-08-26 323-615 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 09 CA
2015-08-26 323-840 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 11 CA
2015-07-02 323-765 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 MONTEBELLO CA
2015-07-02 323-897 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E LSAN DA 08 CA
2015-06-12 323-946 0–9 XXXall 10 · 3 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J LSAN DA 14 CA
2015-05-13 323-749 0–9 XXXall 10 · 4 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K LSAN DA 06 CA
2015-05-05 323-690 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 11 CA
2015-04-13 323-975 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 LSAN DA 03 CA
2015-03-09 323-847 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 13 CA
2015-02-24 323-794 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 14 CA
2015-02-09 323-926 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 MONTEBELLO CA
2015-02-06 323-740 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 LSAN DA 11 CA

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.