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 309
FRONTIER NORTH, INC. - IL 99
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
— 309-556 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-557 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-572 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 MOSSVILLE IL
— 309-576 3XXX which blocks → FRONTIER NORTH, INC. - IL 1015 MOSSVILLE IL
— 309-577 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 MOSSVILLE IL
— 309-578 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 MOSSVILLE IL
— 309-579 0XXX1XXX4XXX5XXX6XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MOSSVILLE IL
— 309-594 0XXX1XXX3XXX5XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 NEPONSET IL
— 309-661 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-662 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-663 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-664 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-695 8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WYOMING IL
— 309-722 1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BELLFLOWER IL
— 309-723 1XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 COLFAX IL
— 309-724 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ELLSWORTH IL
— 309-726 0XXX3XXX4XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 HUDSON IL
— 309-727 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ARROWSMITH IL
— 309-742 0XXX6XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ELMWOOD IL
— 309-745 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 SUNNYLAND IL
— 309-772 7XXX which blocks → FRONTIER NORTH, INC. - IL 1015 BUSHNELL IL
— 309-775 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PRAIRIE CY IL
— 309-784 0XXX1XXX3XXX4XXX7XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 VERMONT IL
— 309-785 1XXX2XXX3XXX4XXX6XXX7XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CUBA IL
— 309-820 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-821 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-823 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-827 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-828 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-829 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-833 9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 MACOMB IL
— 309-836 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 MACOMB IL
— 309-837 8XXX which blocks → FRONTIER NORTH, INC. - IL 1015 MACOMB IL
— 309-852 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1015 KEWANEE IL
— 309-853 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1015 KEWANEE IL
— 309-854 8XXX which blocks → FRONTIER NORTH, INC. - IL 1015 KEWANEE IL
— 309-856 0XXX1XXX which blocks → FRONTIER NORTH, INC. - IL 1015 KEWANEE IL
— 309-862 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-874 4XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MCLEAN IL
— 309-886 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WASHINGTON IL
— 309-888 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BLOOMINGTN IL
— 309-895 3XXX which blocks → FRONTIER NORTH, INC. - IL 1015 BUDA IL
— 309-896 0XXX1XXX2XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ELMIRA IL
— 309-897 0XXX3XXX5XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BRADFORD IL
— 309-923 0XXX3XXX4XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROANOKE IL
— 309-925 0XXX1XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 TREMONT IL
— 309-928 0XXX1XXX4XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 FARMERCITY IL
— 309-932 0XXX1XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 GALVA IL
— 309-962 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1015 LE ROY 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.