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
— 815-561 4XXX5XXX6XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 ROCHELLE IL
— 815-562 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 ROCHELLE IL
— 815-563 0XXX1XXX3XXX5XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 CEDARVILLE IL
— 815-567 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CAMPUS IL
— 815-569 0XXX3XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CAPRON IL
— 815-591 0XXX1XXX4XXX5XXX6XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 HANOVER IL
— 815-594 0XXX1XXX4XXX5XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 APPLERIVER IL
— 815-597 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 GARDENPRRI IL
— 815-598 0XXX4XXX5XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MASSBACH IL
— 815-599 1XXX2XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-623 0XXX4XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROSCOE IL
— 815-624 3XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROCKTON IL
— 815-627 0XXX1XXX4XXX5XXX6XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PAW PAW IL
— 815-628 2XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 W BROOKLYN IL
— 815-629 0XXX3XXX4XXX6XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SHIRLAND IL
— 815-635 0XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CHATSWORTH IL
— 815-638 7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 LA MOILLE IL
— 815-643 3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 DOVER IL
— 815-645 0XXX3XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 STILMANVLY IL
— 815-646 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 TISKILWA IL
— 815-648 0XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 HEBRON IL
— 815-653 8XXX which blocks → FRONTIER NORTH, INC. - IL 1015 WONDERLAKE IL
— 815-659 4XXX5XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BUREAU IL
— 815-663 7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SPRING VLY IL
— 815-664 0XXX3XXX6XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SPRING VLY IL
— 815-672 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 STREATOR IL
— 815-673 0XXX7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 STREATOR IL
— 815-675 5XXX which blocks → FRONTIER NORTH, INC. - IL 1015 SPRING GRV IL
— 815-678 9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 RICHMOND IL
— 815-686 1XXX3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PIPER CITY IL
— 815-688 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 STRAWN IL
— 815-692 0XXX1XXX5XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 FAIRBURY IL
— 815-694 0XXX4XXX6XXX7XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CLIFTON IL
— 815-697 0XXX1XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CHEBANSE IL
— 815-698 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ASHKUM IL
— 815-699 3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WYANET IL
— 815-728 3XXX7XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WONDERLAKE IL
— 815-732 8XXX which blocks → FRONTIER NORTH, INC. - IL 1036 OREGON IL
— 815-734 2XXX3XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MT MORRIS IL
— 815-745 0XXX1XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 WARREN IL
— 815-748 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 DE KALB IL
— 815-752 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 DE KALB IL
— 815-753 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 DE KALB IL
— 815-754 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 DE KALB IL
— 815-756 0XXX which blocks → FRONTIER NORTH, INC. - IL 1036 DE KALB IL
— 815-758 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 DE KALB IL
— 815-765 4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 POPLAR GRV IL
— 815-784 0XXX which blocks → FRONTIER NORTH, INC. - IL 1036 GENOA IL
— 815-786 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 SANDWICH IL
— 815-787 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 DE KALB 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.