NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

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
ILLINOIS BELL TEL CO 157
FRONTIER NORTH, INC. - IL 133
LEVEL 3 COMMUNICATIONS, LLC - IL 76
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 50
AERO NORTH COMMUNICATIONS, INC. - IL 43
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
— 815-226 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 ROCKFORD IL
— 815-227 7XXX which blocks → ILLINOIS BELL TEL CO 9329 ROCKFORD IL
— 815-228 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OGLESBY IL
— 815-229 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 ROCKFORD IL
— 815-230 1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 PLAINFIELD IL
— 815-231 4XXX6XXX8XXX · 3 holders which blocks → ILLINOIS BELL TEL CO 9329 ROCKFORD IL
— 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
— 815-236 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WOODSTOCK IL
— 815-237 1XXX5XXX6XXX9XXX · 4 holders which blocks → ILLINOIS BELL TEL CO 9329 GARDNER IL
— 815-238 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 FREEPORT IL
— 815-239 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1036 PECATONICA IL
— 815-241 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 NORTHBROOK IL
— 815-243 none assigned yet which blocks → UNITED STATES CELLULAR - IL 6265 ROCKFORD IL
— 815-244 not yet reported which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 MT CARROLL IL
— 815-245 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WOODSTOCK 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
— 815-251 1XXX9XXX · 2 holders which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 NELSON IL
— 815-252 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OGLESBY IL
— 815-253 2XXX3XXX4XXX5XXX · 2 holders which blocks → FRONTIER COMMUNICATIONS OF ILLINOIS, INC. 1038 KEMPTON IL
— 815-254 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 PLAINFIELD IL
— 815-256 not yet reported which blocks → STELLE TEL. CO. 1092 STELLE IL
— 815-257 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 STREATOR IL
— 815-258 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JOLIET IL
— 815-259 not yet reported which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 THOMSON IL
— 815-260 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-261 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 CRYSTAL LK IL
— 815-262 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ROCKFORD IL
— 815-263 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 KANKAKEE IL
— 815-264 1XXX2XXX4XXX5XXX6XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1036 WATERMAN IL
— 815-265 0XXX1XXX2XXX3XXX6XXX · 5 holders which blocks → ILLINOIS BELL TEL CO 9329 GILMAN IL
— 815-266 none assigned yet which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-267 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 PLAINFIELD IL
— 815-268 0XXX1XXX5XXX8XXX9XXX · 5 holders which blocks → ILLINOIS BELL TEL CO 9329 ONARGA IL
— 815-269 0XXX1XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 DANFORTH IL
— 815-271 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 MCHENRY IL
— 815-272 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 JOLIET IL
— 815-273 not yet reported which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 SAVANNA IL
— 815-274 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JOLIET IL
— 815-275 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 FREEPORT IL
— 815-276 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 CRYSTAL LK IL
— 815-277 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 FRANKFORT IL
— 815-278 4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 KANKAKEE IL
— 815-279 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 KANKAKEE IL
— 815-280 0XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 JOLIET IL

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.