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 618
FRONTIER NORTH, INC. - IL 126
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
2016-10-18 618-714 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 7 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MASCOUTAH IL
— 618-243 0XXX2XXX3XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 OKAWVILLE IL
— 618-248 0XXX2XXX3XXX4XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 ALBERS IL
— 618-252 9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 HARRISBURG IL
— 618-253 9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 HARRISBURG IL
— 618-262 0XXX1XXX3XXX6XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MT CARMEL IL
— 618-263 1XXX2XXX7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MT CARMEL IL
— 618-265 2XXX which blocks → FRONTIER NORTH, INC. - IL 1036 NEW HAVEN IL
— 618-268 0XXX1XXX2XXX3XXX5XXX7XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 RALEGHGLTI IL
— 618-269 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SHAWNEETN IL
— 618-272 0XXX1XXX2XXX6XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 RIDGWAY IL
— 618-273 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 ELDORADO IL
— 618-295 5XXX6XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MARISSA IL
— 618-298 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BELLMONT IL
— 618-299 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 ALLENDALE IL
— 618-342 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 VILLARIDGE IL
— 618-351 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 CARBONDALE IL
— 618-357 0XXX1XXX4XXX7XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PINCKNEYVL IL
— 618-375 0XXX1XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 GRAYVILLE IL
— 618-378 6XXX which blocks → FRONTIER NORTH, INC. - IL 1036 NORRISCITY IL
— 618-382 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1015 CARMI IL
— 618-384 0XXX1XXX6XXX7XXX8XXX9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 CARMI IL
— 618-392 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 OLNEY IL
— 618-393 0XXX1XXX8XXX9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 OLNEY IL
— 618-395 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 OLNEY IL
— 618-426 0XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 AVA IL
— 618-435 0XXX1XXX7XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BENTON IL
— 618-438 1XXX9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 BENTON IL
— 618-439 1XXX which blocks → FRONTIER NORTH, INC. - IL 1015 BENTON IL
— 618-442 0XXX1XXX2XXX3XXX4XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 PARKERSBG IL
— 618-443 7XXX8XXX which blocks → FRONTIER NORTH, INC. - IL 1015 SPARTA IL
— 618-445 0XXX1XXX6XXX7XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ALBION IL
— 618-453 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 CARBONDALE IL
— 618-455 0XXX1XXX2XXX5XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WILLOWHILL IL
— 618-456 0XXX1XXX4XXX6XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 WEST SALEM IL
— 618-457 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 CARBONDALE IL
— 618-473 0XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 HECKER IL
— 618-476 0XXX2XXX5XXX6XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MILLSTADT IL
— 618-497 0XXX3XXX4XXX6XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PERCY IL
— 618-524 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 METROPOLIS IL
— 618-529 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 CARBONDALE IL
— 618-536 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 CARBONDALE IL
— 618-538 0XXX1XXX2XXX3XXX4XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 WESTVIEW IL
— 618-542 0XXX7XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 DU QUOIN IL
— 618-543 0XXX1XXX2XXX4XXX5XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 JOPPA IL
— 618-544 1XXX which blocks → FRONTIER NORTH, INC. - IL 1015 ROBINSON IL
— 618-546 6XXX7XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROBINSON IL
— 618-549 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 CARBONDALE IL
— 618-557 0XXX2XXX5XXX7XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 HARDINVL IL
— 618-563 0XXX2XXX3XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 HUTSONVL 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.