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 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
2008-03-21 203-690 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 BRIDGEPORT CT
2007-09-11 203-309 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 DARIEN CT
2007-07-13 203-572 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 BRIDGEPORT CT
2007-06-29 203-424 0–9 XXXall 10 · 5 holders which blocks → METROPCS, INC. 5562 DARIEN CT
2007-06-29 203-893 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 ANSONIDRBY CT
2007-02-07 203-873 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BRIDGEPORT CT
2006-11-22 203-728 0–9 XXXall 10 · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 STAMFORD CT
2006-10-30 203-885 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 DANBURY CT
2006-09-05 203-617 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 DANBURY CT
2006-07-20 203-993 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 BRIDGEPORT CT
2006-05-12 203-992 0–9 XXXall 10 · 5 holders which blocks → CSC VOICE, LLC 612K GREENWICH CT
2006-04-06 203-832 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 STAMFORD CT
2006-04-05 203-908 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 BRIDGEPORT CT
2005-02-03 203-508 0–9 XXXall 10 · 2 holders which blocks → PAETEC ITEL, LLC 829J NEW HAVEN CT
2005-01-31 203-307 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 FAIRFIELD CT
2005-01-31 203-540 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BRIDGEPORT CT
2005-01-31 203-898 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 DARIEN CT
2005-01-31 203-990 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 OLDGRNWICH CT
2004-10-15 203-998 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 STAMFORD CT
2004-09-14 203-636 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 DARIEN CT
2004-08-16 203-844 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 FAIRFIELD CT
2004-07-19 203-620 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 DARIEN CT
2004-07-19 203-827 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 OLDGRNWICH CT
2004-03-24 203-280 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 DARIEN CT
2004-03-11 203-347 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 BYRAM CT
2004-02-20 203-920 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 NEW CANAAN CT
2004-02-20 203-955 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 FAIRFIELD CT
2004-02-20 203-986 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 OLDGRNWICH CT
2004-02-12 203-504 0–9 XXXall 10 · 4 holders which blocks → PAETEC ITEL, LLC 829J STAMFORD CT
2004-02-12 203-706 0–9 XXXall 10 · 5 holders which blocks → PAETEC ITEL, LLC 829J WATERBURY CT
2003-10-07 203-369 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 OLDGRNWICH CT
2003-08-19 203-340 0–9 XXXall 10 · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 GREENWICH CT
2003-04-16 203-277 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 OLDGRNWICH CT
2003-04-16 203-310 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 NEW CANAAN CT
2003-04-16 203-320 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 DARIEN CT
2003-04-10 203-742 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 GREENWICH CT
2003-03-28 203-244 0–9 XXXall 10 · 8 holders which blocks → CSC VOICE, LLC 612K RIDGEFIELD CT
2003-03-28 203-276 0–9 XXXall 10 · 2 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
2003-02-04 203-566 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 STAMFORD CT
2003-02-04 203-607 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 STAMFORD CT
2002-11-04 203-809 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 NEW HAVEN CT
2002-10-22 203-273 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 STAMFORD CT
2002-10-04 203-228 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 WATERBURY CT
2002-08-20 203-980 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
2002-07-17 203-704 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WOLCOTT CT
2002-05-30 203-520 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 BRIDGEPORT CT
2002-05-30 203-548 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 STAMFORD CT
2002-05-30 203-808 2XXX3XXX4XXX5XXX7XXX8XXX · 2 holders which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 WATERBURY CT
2002-04-23 203-906 0XXX3XXX4XXX5XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 ANSONIDRBY CT
2002-02-19 203-400 5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 TRUMBULL CT

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.