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 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
2003-03-18 815-580 0–9 XXXall 10 · 8 holders which blocks → AT&T - LOCAL 7421 CHERRY VLY IL
2003-01-23 815-750 not yet reported which blocks → MTCO COMMUNICATIONS, INC. 4837 MARSEILLES IL
2002-10-22 815-718 0–9 XXXall 10 · 4 holders which blocks → UNITED STATES CELLULAR - IL 6265 STERLING IL
2002-10-22 815-990 4XXX5XXX6XXX7XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 FREEPORT IL
2002-09-30 815-608 1XXX2XXX3XXX4XXX5XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
2002-09-30 815-981 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 DE KALB IL
2002-09-03 815-975 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BELVIDERE IL
2002-08-21 815-570 0–9 XXXall 10 · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 SANDWICH IL
2002-07-05 815-712 none assigned yet which blocks → T-MOBILE USA, INC. 6529 LA SALLE IL
2002-07-05 815-719 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → METROPCS, INC. 5562 PRINCETON IL
2002-07-05 815-955 none assigned yet which blocks → METROPCS, INC. 5562 JOLIET IL
2002-07-05 815-970 8XXX9XXX · 2 holders which blocks → METROPCS, INC. 5562 SYCAMORE IL
2002-06-26 815-656 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 FREEPORT IL
2002-06-21 815-566 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 BELVIDERE IL
2002-06-04 815-703 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ROCKFORD IL
2002-06-04 815-930 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 5 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F ELIZABETH IL
2002-06-04 815-960 not yet reported which blocks → NORTH COUNTY COMMUNICATION CORPORATION - CA 7894 LEAF RIVER IL
2002-05-03 815-560 0–9 XXXall 10 · 7 holders which blocks → METROPCS, INC. 5562 HARVARD IL
2002-05-03 815-585 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MORRIS IL
2002-05-03 815-887 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 HARVARD IL
2002-05-03 815-940 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 GARDNER IL
2002-04-02 815-587 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 OTTAWA IL
2002-04-02 815-605 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 GRANT PARK IL
2002-04-02 815-701 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 WOODSTOCK IL
2002-04-02 815-855 0–9 XXXall 10 · 8 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F MILLEDGEVL IL
2002-02-27 815-506 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 UNION IL
2002-02-27 815-513 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MORRIS IL
2002-02-27 815-573 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 KANKAKEE IL
2002-02-27 815-903 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 MCHENRY IL
2002-02-27 815-905 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 LOCKPORT IL
2002-02-04 815-209 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 ROCKFORD IL
2002-02-04 815-215 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → FIRST COMMUNICATIONS, LLC 460K NEW LENOX IL
2002-02-04 815-410 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 LA SALLE IL
2002-02-04 815-515 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 WATSEKA IL
2001-12-28 815-507 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MOMENCE IL
2001-12-28 815-640 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 OTTAWA IL
2001-12-28 815-705 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 MORRIS IL
2001-12-28 815-709 4XXX5XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 COAL CITY IL
2001-12-28 815-915 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 PRINCETON IL
2001-12-06 815-707 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 GILMAN IL
2001-12-06 815-797 1XXX2XXX4XXX7XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 SOMONAUK IL
2001-12-06 815-907 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 8 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MANTENO IL
2001-10-31 815-615 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 MENDOTA IL
2001-10-31 815-716 1XXX5XXX8XXX9XXX · 4 holders which blocks → METROPCS, INC. 5562 STERLING IL
2001-10-24 815-609 not yet reported which blocks → ILLINOIS BELL TEL CO 9329 PLAINFIELD IL
2001-10-23 815-518 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 7 holders which blocks → FIRST COMMUNICATIONS, LLC 460K COAL CITY IL
2001-09-28 815-603 not yet reported which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2001-09-28 815-713 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ROCKFORD IL
2001-09-28 815-802 6XXX which blocks → ILLINOIS BELL TEL CO 9329 KANKAKEE IL
2001-09-28 815-912 0XXX2XXX · 2 holders which blocks → AERO NORTH COMMUNICATIONS, INC. - IL 443F BELVIDERE 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.