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
— 815-282 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 ROCKFORD IL
— 815-284 not yet reported which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 DIXON IL
— 815-285 not yet reported which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 DIXON IL
— 815-286 0XXX1XXX2XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 HINCKLEY IL
— 815-287 0XXX1XXX3XXX7XXX8XXX9XXX · 6 holders which blocks → ILLINOIS BELL TEL CO 9329 VERONA IL
— 815-288 not yet reported which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 DIXON IL
— 815-289 none assigned yet which blocks → UNITED STATES CELLULAR - IL 6265 ROCKFORD IL
— 815-291 none assigned yet which blocks → UNITED STATES CELLULAR - IL 6265 FREEPORT IL
— 815-292 not yet reported which blocks → BERGEN TEL. CO. - IL 0980 SO BERGEN IL
— 815-293 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ILLINOIS BELL TEL CO 9329 LOCKPORT IL
— 815-294 not yet reported which blocks → SPOK, INC. 6630 LA GRANGE IL
— 815-295 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 KANKAKEE IL
— 815-297 7XXX which blocks → FRONTIER NORTH, INC. - IL 1036 FREEPORT IL
— 815-298 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ROCKFORD IL
— 815-299 8XXX which blocks → UNITED STATES CELLULAR - IL 6265 ROCKFORD IL
— 815-301 0XXX4XXX7XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CRYSTAL LK IL
— 815-302 2XXX which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-303 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 PRINCETON IL
— 815-304 0XXX1XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 KANKAKEE IL
— 815-305 1XXX2XXX3XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 GARDNER IL
— 815-306 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 LOCKPORT IL
— 815-307 0XXX1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MCHENRY IL
— 815-308 0XXX1XXX2XXX4XXX5XXX6XXX8XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 WOODSTOCK IL
— 815-310 0XXX1XXX2XXX3XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 UTICA IL
— 815-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX IL
— 815-313 0XXX2XXX3XXX4XXX5XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 OTTAWA IL
— 815-314 0XXX1XXX2XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MANHATTAN IL
— 815-315 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 ROCKFORD IL
— 815-316 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 ROCKFORD IL
— 815-317 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 CRESCENTCY IL
— 815-318 0XXX1XXX2XXX3XXX4XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MORRIS IL
— 815-319 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → UNITED STATES CELLULAR - IL 6265 ROCKFORD IL
— 815-321 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC 224C WOODSTOCK IL
— 815-322 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MCHENRY IL
— 815-325 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JOLIET IL
— 815-326 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OGLESBY IL
— 815-327 not yet reported which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 PLAINFIELD IL
— 815-328 4XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 LOCKPORT IL
— 815-330 not yet reported which blocks → FIRST COMMUNICATIONS, LLC 460K CRESCENTCY IL
— 815-331 4XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MCHENRY IL
— 815-332 0XXX which blocks → FRONTIER NORTH, INC. - IL 1015 CHERRY VLY IL
— 815-333 6XXX7XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 WOODSTOCK IL
— 815-334 7XXX9XXX · 2 holders which blocks → ILLINOIS BELL TEL CO 9329 WOODSTOCK IL
— 815-335 0XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WINNEBAGO IL
— 815-336 3XXX4XXX5XXX6XXX · 2 holders which blocks → CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL 1183 COLETA IL
— 815-337 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 WOODSTOCK IL
— 815-338 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 WOODSTOCK IL
— 815-339 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1036 GRANVILLE IL
— 815-341 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JOLIET IL
— 815-342 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 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.