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
CABLEVISION LIGHTPATH, INC. - CT 29
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
2011-05-25 203-489 0–9 XXXall 10 · 6 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 GREENWICH CT
2011-04-04 203-970 0–9 XXXall 10 · 3 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 NORWALK CT
2010-07-13 203-693 0–9 XXXall 10 · 8 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 MILFORD CT
2008-09-15 203-960 0–9 XXXwhole prefix which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
2003-08-19 203-340 0–9 XXXall 10 · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 GREENWICH CT
2003-03-28 203-276 0–9 XXXall 10 · 2 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
2001-07-27 203-810 0–9 XXXall 10 · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 NORWALK CT
2001-01-30 203-956 0XXX which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 NORWALK CT
— 203-202 0XXX1XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 DARIEN CT
— 203-210 5XXX7XXX8XXX · 2 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 WILTON CT
— 203-220 1XXX2XXX3XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 TRUMBULL CT
— 203-242 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 HUNTINGTON CT
— 203-252 0–9 XXXall 10 · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
— 203-283 1XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 MILFORD CT
— 203-292 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 FAIRFIELD CT
— 203-298 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 NEW HAVEN CT
— 203-344 0XXX1XXX2XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 OLDGRNWICH CT
— 203-345 none assigned yet which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 BRIDGEPORT CT
— 203-354 none assigned yet which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 NORWALK CT
— 203-355 not yet reported which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
— 203-485 2XXX6XXX which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 GREENWICH CT
— 203-557 0XXX3XXX4XXX6XXX8XXX which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 WESTPORT CT
— 203-569 3XXX7XXX9XXX which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
— 203-588 none assigned yet which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
— 203-594 1XXX2XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 NEW CANAAN CT
— 203-628 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 DANBURY CT
— 203-817 0–9 XXXall 10 · 3 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 STAMFORD CT
— 203-870 0XXX1XXX4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 BRIDGEPORT CT
— 203-971 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CABLEVISION LIGHTPATH, INC. - CT 4950 GREENWICH 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.