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 860
SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 325
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 63
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 60
TELEPORT COMMUNICATIONS AMERICA, LLC - CT 56
PAETEC ITEL, LLC 50
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
— 860-521 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-522 9XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-523 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-524 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-525 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-526 7XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 DEEP RIVER CT
— 860-527 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-528 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-529 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-530 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J COLUMBIA CT
— 860-531 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CT 7143 COLCHESTER CT
— 860-532 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CT 7143 DEEP RIVER CT
— 860-533 none assigned yet which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 MANCHESTER CT
— 860-534 0XXX1XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-535 6XXX7XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 MYSTIC CT
— 860-536 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 MYSTIC CT
— 860-537 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 COLCHESTER CT
— 860-539 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 HARTFORD CT
— 860-540 3XXX4XXX5XXX6XXX7XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J BRISTOL CT
— 860-541 0XXX1XXX5XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-542 0XXX2XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 NORFOLK CT
— 860-543 none assigned yet which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-544 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 COVENTRY CT
— 860-545 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-546 3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 CANTERBURY CT
— 860-547 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-548 6XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-549 2XXX3XXX4XXX6XXX7XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-550 none assigned yet which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-551 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 XXXXXXXXXX CT
— 860-552 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - CT 4800 CLINTON CT
— 860-553 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → PAETEC ITEL, LLC 829J STORRS CT
— 860-554 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HADDAM CT
— 860-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST CT
— 860-556 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CT 7143 CANTERBURY CT
— 860-557 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-558 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 HARTFORD CT
— 860-559 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 6388 HARTFORD CT
— 860-560 1XXX3XXX6XXX8XXX · 3 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-561 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-563 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-564 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 PLAINFIELD CT
— 860-565 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-566 0XXX8XXX9XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-567 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 LITCHFIELD CT
— 860-568 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-569 9XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-570 not yet reported which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-571 1XXX which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 HARTFORD CT
— 860-572 3XXX6XXX · 2 holders which blocks → SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT 9147 MYSTIC 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.