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
— 815-649 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 GARDNER IL
— 815-650 0–9 XXXall 10 · 5 holders which blocks → METROPCS, INC. 5562 FREEPORT IL
— 815-651 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 JOLIET IL
— 815-652 1XXX which blocks → BRIGHTSPEED OF ILLINOIS, LLC 1057 GRANDDTOUR IL
— 815-653 8XXX which blocks → FRONTIER NORTH, INC. - IL 1015 WONDERLAKE IL
— 815-654 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 ROCKFORD IL
— 815-657 1XXX2XXX4XXX5XXX9XXX · 3 holders which blocks → ILLINOIS BELL TEL CO 9329 FORREST IL
— 815-659 4XXX5XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 BUREAU IL
— 815-660 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 LOCKPORT IL
— 815-661 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 MORRIS IL
— 815-662 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MOMENCE IL
— 815-663 7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SPRING VLY IL
— 815-664 0XXX3XXX6XXX8XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 SPRING VLY IL
— 815-665 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 OTTAWA IL
— 815-667 0XXX1XXX8XXX · 3 holders which blocks → ILLINOIS BELL TEL CO 9329 UTICA IL
— 815-669 0XXX1XXX2XXX5XXX6XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MCHENRY IL
— 815-670 0XXX2XXX which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
— 815-671 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 JOLIET IL
— 815-672 not yet reported which blocks → FRONTIER NORTH, INC. - IL 1015 STREATOR IL
— 815-673 0XXX7XXX8XXX9XXX · 2 holders which blocks → FRONTIER NORTH, INC. - IL 1015 STREATOR IL
— 815-674 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 STREATOR IL
— 815-675 5XXX which blocks → FRONTIER NORTH, INC. - IL 1015 SPRING GRV IL
— 815-676 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 PLAINFIELD IL
— 815-678 9XXX which blocks → FRONTIER NORTH, INC. - IL 1015 RICHMOND IL
— 815-679 4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 MCHENRY IL
— 815-680 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 MANHATTAN IL
— 815-682 0XXX1XXX2XXX5XXX6XXX7XXX · 5 holders which blocks → FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL 1000 STOCKLAND IL
— 815-683 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → ILLINOIS BELL TEL CO 9329 CRESCENTCY IL
— 815-684 not yet reported which blocks → CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL 1183 CHADWICK IL
— 815-685 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JOLIET IL
— 815-686 1XXX3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → FRONTIER NORTH, INC. - IL 1015 PIPER CITY IL
— 815-687 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 WOODSTOCK IL
— 815-688 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 STRAWN IL
— 815-689 not yet reported which blocks → FRONTIER COMMUNICATIONS OF ILLINOIS, INC. 1038 CULLOM IL
— 815-690 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-691 0XXX1XXX2XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 8702 UTICA IL
— 815-692 0XXX1XXX5XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 FAIRBURY IL
— 815-693 none assigned yet which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
— 815-694 0XXX4XXX6XXX7XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CLIFTON IL
— 815-695 0XXX2XXX6XXX · 3 holders which blocks → ILLINOIS BELL TEL CO 9329 NEWARK IL
— 815-697 0XXX1XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 CHEBANSE IL
— 815-698 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FRONTIER NORTH, INC. - IL 1015 ASHKUM IL
— 815-699 3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH, INC. - IL 1015 WYANET IL
— 815-700 not yet reported which blocks → IL
— 815-702 0XXX1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 6 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J SAUNEMIN IL
— 815-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX IL
— 815-714 0–9 XXXall 10 · 7 holders which blocks → BANDWIDTH.COM CLEC, LLC - IL 984E JOLIET IL
— 815-717 0XXX1XXX3XXX4XXX6XXX8XXX · 5 holders which blocks → FIRST COMMUNICATIONS, LLC 460K NEW LENOX IL
— 815-720 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 ROCKFORD IL
— 815-721 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 ROCKFORD 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.