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 217
FRONTIER NORTH, INC. - IL 114
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
2016-10-27 217-616 0XXX1XXX2XXX3XXX4XXX6XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 AUBURN IL
2001-05-18 217-838 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1015 LINCOLN IL
— 217-225 0XXX1XXX2XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 VERSAILLES IL
— 217-236 0XXX1XXX2XXX6XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PERRY IL
— 217-243 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 JACKSONVL IL
— 217-245 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 JACKSONVL IL
— 217-253 7XXX8XXX which blocks → FRONTIER NORTH, INC. - IL 1015 TUSCOLA IL
— 217-262 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 HAMMOND IL
— 217-269 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CHRISMAN IL
— 217-275 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 VERMILION IL
— 217-279 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WEST UNION IL
— 217-285 0XXX3XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PITTSFIELD IL
— 217-286 1XXX2XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 HENNING IL
— 217-288 2XXX3XXX4XXX6XXX7XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SIDELL IL
— 217-291 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 JACKSONVL IL
— 217-335 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BARRY IL
— 217-336 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 BAYLIS IL
— 217-368 0XXX5XXX6XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 GREENFIELD IL
— 217-374 0XXX3XXX4XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WHITE HALL IL
— 217-379 0XXX1XXX7XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PAXTON IL
— 217-385 0XXX3XXX4XXX7XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BROCTON IL
— 217-386 1XXX3XXX4XXX5XXX6XXX7XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 LODA IL
— 217-387 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 THAWVILLE IL
— 217-388 1XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MELVIN IL
— 217-394 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BUCKLEY IL
— 217-395 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROBERTS IL
— 217-426 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 NEW CANTON IL
— 217-432 2XXX3XXX4XXX6XXX7XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 HULL IL
— 217-435 0XXX1XXX4XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WAVERLY IL
— 217-436 0XXX3XXX6XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PALMYRA IL
— 217-437 0XXX1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROCKPORT IL
— 217-438 0XXX1XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 AUBURN IL
— 217-445 0XXX1XXX4XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MDLTNNWHLD IL
— 217-463 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 PARIS IL
— 217-465 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 PARIS IL
— 217-466 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 PARIS IL
— 217-468 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 OREANA IL
— 217-472 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CHAPIN IL
— 217-478 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ALEXANDER IL
— 217-479 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 JACKSONVL IL
— 217-483 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 CHATHAM IL
— 217-486 0XXX1XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ILLIOPOLIS IL
— 217-488 0XXX1XXX4XXX5XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 NEW BERLIN IL
— 217-489 3XXX6XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MANSFIELD IL
— 217-496 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SHERMAN IL
— 217-566 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WILLIAMSVL IL
— 217-584 0XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MEREDOSIA IL
— 217-586 9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 MAHOMET IL
— 217-587 0XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MANCHESTER IL
— 217-589 0XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ROODHOUSE 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.