NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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
Clear Download CSV ↓
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 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.