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 631
TC SYSTEMS, INC. - NY 34
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
2018-09-06 631-607 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 7 holders which blocks → TC SYSTEMS, INC. - NY 7140 WADING RIV NY
2013-10-08 631-437 0–9 XXXall 10 · 6 holders which blocks → TC SYSTEMS, INC. - NY 7140 FIREISLAND NY
— 631-213 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TC SYSTEMS, INC. - NY 7140 MIDLAND NY
— 631-239 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TC SYSTEMS, INC. - NY 7140 NORTHPORT NY
— 631-247 0XXX3XXX6XXX7XXX9XXX · 3 holders which blocks → TC SYSTEMS, INC. - NY 7140 FARMINGDL NY
— 631-256 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TC SYSTEMS, INC. - NY 7140 SAYVILLE NY
— 631-312 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → TC SYSTEMS, INC. - NY 7140 PATCHOGUE NY
— 631-370 7XXX which blocks → TC SYSTEMS, INC. - NY 7140 FARMINGDL NY
— 631-380 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TC SYSTEMS, INC. - NY 7140 STONYBROOK NY
— 631-387 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → TC SYSTEMS, INC. - NY 7140 COMMACK NY
— 631-457 0XXX2XXX3XXX9XXX · 2 holders which blocks → TC SYSTEMS, INC. - NY 7140 BRENTWOOD NY
— 631-503 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TC SYSTEMS, INC. - NY 7140 CTRMORICHS NY
— 631-561 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TC SYSTEMS, INC. - NY 7140 SELDEN NY
— 631-619 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TC SYSTEMS, INC. - NY 7140 RONKONKOMA NY
— 631-623 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TC SYSTEMS, INC. - NY 7140 W COMMACK NY
— 631-639 0–9 XXXall 10 · 2 holders which blocks → TC SYSTEMS, INC. - NY 7140 BRENTWOOD NY
— 631-655 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TC SYSTEMS, INC. - NY 7140 RIVERHEAD NY
— 631-688 0XXX2XXX which blocks → TC SYSTEMS, INC. - NY 7140 FARMINGDL NY
— 631-693 1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 3 holders which blocks → TC SYSTEMS, INC. - NY 7140 AMITYVILLE NY
— 631-701 1XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TC SYSTEMS, INC. - NY 7140 EASTPORT NY
— 631-712 7XXX8XXX9XXX which blocks → TC SYSTEMS, INC. - NY 7140 FARMINGDL NY
— 631-715 0XXX4XXX5XXX9XXX · 4 holders which blocks → TC SYSTEMS, INC. - NY 7140 CENTRAISLP NY
— 631-729 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TC SYSTEMS, INC. - NY 7140 ATLANTIC NY
— 631-760 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TC SYSTEMS, INC. - NY 7140 HUNTINGTON NY
— 631-784 0XXX3XXX4XXX5XXX6XXX8XXX · 6 holders which blocks → TC SYSTEMS, INC. - NY 7140 CENTRAISLP NY
— 631-787 2XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TC SYSTEMS, INC. - NY 7140 CENTRAISLP NY
— 631-792 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TC SYSTEMS, INC. - NY 7140 BABYLON NY
— 631-823 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → TC SYSTEMS, INC. - NY 7140 BAYPORT NY
— 631-866 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TC SYSTEMS, INC. - NY 7140 BELLPORT NY
— 631-894 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TC SYSTEMS, INC. - NY 7140 BAY SHORE NY
— 631-918 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TC SYSTEMS, INC. - NY 7140 DEER PARK NY
— 631-960 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TC SYSTEMS, INC. - NY 7140 ISLIP NY
— 631-973 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → TC SYSTEMS, INC. - NY 7140 KINGS PARK NY
— 631-991 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TC SYSTEMS, INC. - NY 7140 LINDENHST NY

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.