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
— 203-799 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NEW HAVEN CT
— 203-801 1XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NEW CANAAN CT
— 203-803 1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NORWALK CT
— 203-804 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 NEW HAVEN CT
— 203-805 1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CT 7143 WATERBURY CT
— 203-806 0XXX1XXX3XXX4XXX5XXX7XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CT 7143 CHESHIRE CT
— 203-811 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX CT
— 203-812 0XXX8XXX9XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NEW HAVEN CT
— 203-813 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → TC SYSTEMS, INC. - NY 7140 BYRAM CT
— 203-814 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 BRIDGEPORT CT
— 203-815 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NEW HAVEN CT
— 203-817 0–9 XXXall 10 · 3 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
— 203-818 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CT 7230 NORWALK CT
— 203-819 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WATERBURY CT
— 203-820 0XXX2XXX · 2 holders which blocks → METROPCS, INC. 5562 NORWALK CT
— 203-821 1XXX7XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NEW HAVEN CT
— 203-822 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → AT&T - LOCAL 7421 NORWALK CT
— 203-823 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J NEW HAVEN CT
— 203-824 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 NEW HAVEN CT
— 203-825 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DANBURY CT
— 203-826 0–9 XXXall 10 · 6 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DANBURY CT
— 203-828 0XXX1XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 SEYMOUR CT
— 203-829 0XXX which blocks → OMNIPOINT COMMUNICATIONS, INC. - CT 6624 NORWALK CT
— 203-830 none assigned yet which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DANBURY CT
— 203-831 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-834 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 WILTON CT
— 203-835 not yet reported which blocks → SPOK, INC. 6630 NORWALK CT
— 203-837 1XXX6XXX7XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DANBURY CT
— 203-838 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-839 not yet reported which blocks → SPOK, INC. 6630 NORWALK CT
— 203-840 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-841 5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → PAETEC ITEL, LLC 829J WATERBURY CT
— 203-842 0XXX1XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NORWALK CT
— 203-843 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 NEW HAVEN CT
— 203-845 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-846 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-847 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-848 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J NEW HAVEN CT
— 203-849 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-851 2XXX3XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-852 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-853 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-854 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-855 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-856 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NORWALK CT
— 203-857 1XXX9XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORWALK CT
— 203-858 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 NORWALK CT
— 203-859 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEW HAVEN CT
— 203-860 not yet reported which blocks → CT
— 203-861 not yet reported which blocks → VERIZON NEW YORK, INC. 9104 GREENWICH 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.