NumberResearch Membership · Data 09/26/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/26/2026

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 815
FRONTIER NORTH, INC. - IL 133
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
— 815-789 0XXX1XXX2XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1036 ORANGEVL IL
— 815-824 0XXX1XXX3XXX4XXX5XXX6XXX7XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1036 SHABBONA IL
— 815-825 0XXX1XXX3XXX4XXX5XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MALTA IL
— 815-827 0XXX1XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MAPLE PARK IL
— 815-842 7XXX which blocks → FRONTIER NORTH, INC. - IL 1015 PONTIAC IL
— 815-844 0XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PONTIAC IL
— 815-845 0XXX1XXX3XXX4XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 SCALESMOND IL
— 815-849 0XXX1XXX2XXX3XXX4XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 SUBLETTE IL
— 815-853 1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WENONA IL
— 815-854 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 LONG POINT IL
— 815-857 1XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 AMBOY IL
— 815-858 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 ELIZABETH IL
— 815-863 0XXX2XXX4XXX6XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 RUTLAND IL
— 815-865 0XXX1XXX2XXX3XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1036 DAVIS IL
— 815-868 0XXX1XXX4XXX6XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MCCONNELL IL
— 815-869 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MAGNOLIA IL
— 815-872 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 PRINCETON IL
— 815-873 2XXX6XXX7XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 NEWMILFORD IL
— 815-874 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 NEWMILFORD IL
— 815-875 7XXX which blocks → FRONTIER NORTH, INC. - IL 1015 PRINCETON IL
— 815-876 0XXX4XXX6XXX7XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PRINCETON IL
— 815-879 6XXX which blocks → FRONTIER NORTH, INC. - IL 1015 PRINCETON IL
— 815-885 0XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROCK CUT IL
— 815-894 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 LADD IL
— 815-895 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 SYCAMORE IL
— 815-899 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 SYCAMORE IL
— 815-925 1XXX3XXX5XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 HENNEPIN IL
— 815-934 1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 EMINGTON IL
— 815-938 0XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 FORRESTON IL
— 815-945 0XXX1XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CHENOA IL
— 815-947 0XXX1XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 STOCKTON IL
— 815-949 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CABERY IL
— 815-998 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ODELL IL

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/26/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.