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 203
SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 338
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 61
NEW CINGULAR WIRELESS PCS, LLC - DC 52
OMNIPOINT COMMUNICATIONS, INC. - CT 47
LEVEL 3 COMMUNICATIONS, LLC - CT 41
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
2024-09-18 203-203 0–9 XXXwhole prefix which blocks → ONVOY, LLC - CT 639C GREENWICH CT
2021-12-06 203-670 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 FAIRFIELD CT
2015-11-10 203-390 0–9 XXXall 10 · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CT 7143 NEW HAVEN CT
2015-07-29 203-833 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
2013-11-14 203-290 0–9 XXXall 10 · 7 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 BRIDGEPORT CT
2013-09-26 203-666 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 BRIDGEPORT CT
2012-10-31 203-680 0–9 XXXall 10 · 4 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NEW HAVEN CT
2012-10-02 203-580 0–9 XXXall 10 · 5 holders which blocks → PEERLESS NETWORK OF CONNECTICUT, LLC - CT 539F BYRAM CT
2012-10-02 203-780 0–9 XXXall 10 · 5 holders which blocks → PEERLESS NETWORK OF CONNECTICUT, LLC - CT 539F NEW HAVEN CT
2012-04-16 203-760 0–9 XXXwhole prefix which blocks → PEERLESS NETWORK OF CONNECTICUT, LLC - CT 539F BRIDGEPORT CT
2012-02-24 203-900 0–9 XXXall 10 · 6 holders which blocks → CSC VOICE, LLC 612K GREENWICH CT
2012-02-24 203-914 0–9 XXXall 10 · 2 holders which blocks → CSC VOICE, LLC 612K STAMFORD CT
2012-01-18 203-343 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ANSONIDRBY CT
2011-12-06 203-456 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 DANBURY CT
2011-12-06 203-836 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
2011-05-25 203-489 0–9 XXXall 10 · 6 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 GREENWICH CT
2011-05-25 203-957 0–9 XXXall 10 · 4 holders which blocks → CSC VOICE, LLC 612K NORWALK CT
2011-05-18 203-997 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 ANSONIDRBY CT
2011-04-04 203-970 0–9 XXXall 10 · 3 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 NORWALK CT
2011-03-18 203-590 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 TRUMBULL CT
2011-03-10 203-707 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 WATERBURY CT
2011-03-10 203-800 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 NEW HAVEN CT
2011-03-09 203-999 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 NEW HAVEN CT
2011-03-07 203-864 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 BRIDGEPORT CT
2011-02-09 203-519 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 WATERBURY CT
2011-01-28 203-717 0–9 XXXall 10 · 5 holders which blocks → CSC VOICE, LLC 612K GREENWICH CT
2010-12-16 203-361 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NEW HAVEN CT
2010-11-08 203-892 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 ANSONIDRBY CT
2010-09-21 203-941 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CT 199F SEYMOUR CT
2010-09-08 203-726 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 BRIDGEPORT CT
2010-07-13 203-693 0–9 XXXall 10 · 8 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 MILFORD CT
2010-07-09 203-501 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 DANBURY CT
2010-07-09 203-584 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
2010-02-12 203-491 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - CT 199F NEWTOWN CT
2008-12-10 203-360 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 BRIDGEPORT CT
2008-10-23 203-212 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BRIDGEPORT CT
2008-10-22 203-308 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 ANSONIDRBY CT
2008-10-22 203-917 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 DANBURY CT
2008-10-08 203-995 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 BRIDGEPORT CT
2008-10-03 203-600 0–9 XXXall 10 · 2 holders which blocks → METROPCS, INC. 5562 MERIDEN CT
2008-10-03 203-684 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 NEW HAVEN CT
2008-10-03 203-802 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 WATERBURY CT
2008-10-03 203-850 0–9 XXXall 10 · 2 holders which blocks → METROPCS, INC. 5562 NEW HAVEN CT
2008-09-15 203-960 0–9 XXXwhole prefix which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
2008-09-12 203-936 0–9 XXXall 10 · 3 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NEW HAVEN CT
2008-08-20 203-897 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 STAMFORD CT
2008-08-14 203-200 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - CT 199F NEW HAVEN CT
2008-06-25 203-939 0–9 XXXall 10 · 3 holders which blocks → CSC VOICE, LLC 612K NORWALK CT
2008-05-13 203-909 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
2008-05-12 203-450 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 BRIDGEPORT CT

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.