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
Clear Download CSV ↓
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 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.