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
— 203-628 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 DANBURY CT
— 203-629 not yet reported which blocks → VERIZON NEW YORK, INC. 9104 GREENWICH CT
— 203-630 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 MERIDEN CT
— 203-631 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 MERIDEN CT
— 203-632 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J NAUGATUCK CT
— 203-633 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WOLCOTT CT
— 203-634 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 MERIDEN CT
— 203-635 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WESTPORT CT
— 203-637 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 OLDGRNWICH CT
— 203-638 4XXX8XXX which blocks → PAETEC ITEL, LLC 829J TRUMBULL CT
— 203-639 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 MERIDEN CT
— 203-640 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 NEW HAVEN CT
— 203-641 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
— 203-642 3XXX4XXX6XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 NORWALK CT
— 203-643 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J BRANFORD CT
— 203-644 1XXX3XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NORWALK CT
— 203-645 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 NEW HAVEN CT
— 203-646 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - CT 639C BRANFORD CT
— 203-647 not yet reported which blocks → PAETEC ITEL, LLC 829J MILFORD CT
— 203-648 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 DANBURY CT
— 203-649 8XXX which blocks → PAETEC ITEL, LLC 829J CHESHIRE CT
— 203-651 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J CHESHIRE CT
— 203-652 8XXX which blocks → PAETEC ITEL, LLC 829J NEW CANAAN CT
— 203-653 8XXX which blocks → PAETEC ITEL, LLC 829J STAMFORD CT
— 203-654 0XXX1XXX2XXX3XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NEW HAVEN CT
— 203-655 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DARIEN CT
— 203-656 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DARIEN CT
— 203-657 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 NEW HAVEN CT
— 203-658 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CT 7143 STAMFORD CT
— 203-659 8XXX which blocks → PAETEC ITEL, LLC 829J FAIRFIELD CT
— 203-661 not yet reported which blocks → VERIZON NEW YORK, INC. 9104 GREENWICH CT
— 203-662 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DARIEN CT
— 203-663 3XXX which blocks → PAETEC ITEL, LLC 829J NORWALK CT
— 203-664 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → CSC VOICE, LLC 612K REDDING CT
— 203-665 4XXX8XXX · 2 holders which blocks → PAETEC ITEL, LLC 829J WILTON CT
— 203-667 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 STAMFORD CT
— 203-668 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 NEW HAVEN CT
— 203-669 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 DARIEN CT
— 203-671 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
— 203-672 not yet reported which blocks → PAETEC ITEL, LLC 829J NEW HAVEN CT
— 203-673 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → AT&T - LOCAL 7421 BRIDGEPORT CT
— 203-674 1XXX8XXX9XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 STAMFORD CT
— 203-675 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 NEW HAVEN CT
— 203-676 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 NEW HAVEN CT
— 203-677 0XXX1XXX4XXX8XXX9XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 WALLINGFD CT
— 203-678 4XXX8XXX9XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J WALLINGFD CT
— 203-679 1XXX2XXX9XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 WALLINGFD CT
— 203-681 0XXX1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON NEW YORK, INC. 9104 BYRAM CT
— 203-682 3XXX5XXX · 2 holders which blocks → PAETEC ITEL, LLC 829J WESTPORT CT
— 203-683 8XXX which blocks → PAETEC ITEL, LLC 829J 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.