NumberResearch Membership · Data 09/23/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/23/2026

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
— 815-232 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-233 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-234 0XXX1XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BYRON IL
— 815-235 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-239 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1036 PECATONICA IL
— 815-246 0XXX1XXX2XXX3XXX5XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 EARLVILLE IL
— 815-247 0XXX1XXX2XXX3XXX4XXX5XXX7XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1036 SEWARD IL
— 815-248 0XXX1XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 DURAND IL
— 815-249 1XXX2XXX4XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 GRANDRIDGE IL
— 815-264 1XXX2XXX4XXX5XXX6XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 WATERMAN IL
— 815-266 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-286 0XXX1XXX2XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 HINCKLEY IL
— 815-297 7XXX which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-332 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 CHERRY VLY IL
— 815-335 0XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WINNEBAGO IL
— 815-339 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 GRANVILLE IL
— 815-362 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 GERMAN VLY IL
— 815-365 1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 REDDICK IL
— 815-367 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 WINSLOW IL
— 815-368 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 LOSTANT IL
— 815-369 0XXX1XXX6XXX7XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 LENA IL
— 815-376 1XXX3XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 OHIO IL
— 815-379 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WALNUT IL
— 815-384 0XXX1XXX2XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 CRESTON IL
— 815-393 1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 MONROE CTR IL
— 815-396 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 STEWARD IL
— 815-406 0XXX1XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BYRON IL
— 815-428 0XXX1XXX4XXX5XXX6XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MARTINTON IL
— 815-429 0XXX1XXX2XXX6XXX7XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SHELDON IL
— 815-435 0XXX1XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BEAVERVL IL
— 815-437 1XXX3XXX4XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 PUTNAM IL
— 815-443 0XXX1XXX3XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 PEARL CITY IL
— 815-445 4XXX5XXX7XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MANLIUS IL
— 815-446 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1036 CEDARPOINT IL
— 815-449 0XXX1XXX3XXX4XXX5XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1036 DAKOTA IL
— 815-452 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 TOLUCA IL
— 815-453 0XXX1XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 ASHTON IL
— 815-454 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SHEFFIELD IL
— 815-456 1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 FRANKLIGRV IL
— 815-486 0XXX1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 DONOVAN IL
— 815-492 1XXX4XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 APPLERIVER IL
— 815-495 0XXX1XXX5XXX6XXX7XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 LELAND IL
— 815-496 0XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SHERIDAN IL
— 815-497 3XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 COMPTON IL
— 815-498 0XXX5XXX6XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SOMONAUK IL
— 815-522 0XXX1XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 KIRKLAND IL
— 815-538 8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MENDOTA IL
— 815-539 4XXX8XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 MENDOTA IL
— 815-544 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BELVIDERE IL
— 815-547 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 BELVIDERE IL

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/23/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.