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
2006-09-22 815-993 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OGLESBY IL
2006-08-31 815-904 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ROCKFORD IL
2006-08-30 815-666 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 JOLIET IL
2006-08-25 815-250 0–9 XXXall 10 · 5 holders which blocks → COMCAST IP PHONE, LLC 318J LA SALLE IL
2006-08-25 815-340 0XXX1XXX3XXX7XXX8XXX9XXX · 6 holders which blocks → COMCAST IP PHONE, LLC 318J LA MOILLE IL
2006-07-24 815-630 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2006-07-18 815-309 not yet reported which blocks → AERO NORTH COMMUNICATIONS, INC. - IL 443F SHANNON IL
2006-07-18 815-952 not yet reported which blocks → AERO NORTH COMMUNICATIONS, INC. - IL 443F LANARK IL
2006-06-23 815-708 0–9 XXXall 10 · 4 holders which blocks → COMCAST IP PHONE, LLC 318J ROCKFORD IL
2006-06-20 815-200 0–9 XXXall 10 · 3 holders which blocks → PAETEC ITEL, LLC 829J LA SALLE IL
2006-06-15 815-980 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ROCKFORD IL
2006-06-06 815-219 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 CRYSTAL LK IL
2006-04-21 815-571 0XXX1XXX2XXX4XXX5XXX7XXX · 5 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F SHANNON IL
2006-04-21 815-906 0–9 XXXall 10 · 6 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F MT CARROLL IL
2006-02-16 815-731 0–9 XXXwhole prefix which blocks → ILLINOIS BELL TEL CO 9329 PLAINFIELD IL
2006-02-13 815-770 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → CHARTER IP ENABLED SERVICES, LLC 792K HARVARD IL
2006-02-10 815-290 0–9 XXXall 10 · 9 holders which blocks → AT&T ENTERPRISES, LLC 516C MINOOKA IL
2006-02-10 815-596 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → AT&T ENTERPRISES, LLC 516C MARENGO IL
2005-11-22 815-920 0XXX9XXX · 2 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F CORNELL IL
2005-10-25 815-760 0XXX1XXX2XXX7XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 BUREAU IL
2005-10-06 815-581 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → COMCAST IP PHONE, LLC 318J SPRING GRV IL
2005-10-06 815-582 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2005-08-18 815-409 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 JOLIET IL
2005-04-21 815-992 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 STREATOR IL
2005-04-18 815-847 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → AT&T ENTERPRISES, LLC 516C ROCKFORD IL
2005-03-17 815-677 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 DIXON IL
2005-02-22 815-957 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 ROCKTON IL
2005-02-14 815-901 0–9 XXXall 10 · 3 holders which blocks → COMCAST IP PHONE, LLC 318J DE KALB IL
2005-02-10 815-323 0–9 XXXall 10 · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - IL 6115 BELVIDERE IL
2005-01-04 815-989 0–9 XXXall 10 · 8 holders which blocks → MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 846F PROPHETSTN IL
2004-12-30 815-893 0–9 XXXall 10 · 7 holders which blocks → COMCAST IP PHONE, LLC 318J CRYSTAL LK IL
2004-10-14 815-390 0–9 XXXall 10 · 8 holders which blocks → COMCAST IP PHONE, LLC 318J BRAIDWOOD IL
2004-10-14 815-414 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 EARLVILLE IL
2004-09-29 815-213 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → UNITED STATES CELLULAR - IL 6265 STERLING IL
2004-07-27 815-450 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MOMENCE IL
2004-06-28 815-517 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 DE KALB IL
2004-06-16 815-508 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DE KALB IL
2004-06-15 815-281 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → UNITED STATES CELLULAR - IL 6265 GALENA IL
2004-05-12 815-826 0XXX1XXX2XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 SOMONAUK IL
2004-01-07 815-616 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 FREEPORT IL
2003-10-02 815-595 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 8 holders which blocks → AT&T - LOCAL 7421 OREGON IL
2003-07-14 815-590 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 STERLING IL
2003-07-14 815-600 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JOLIET IL
2003-07-14 815-999 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 JOLIET IL
2003-06-25 815-977 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 ROCKFORD IL
2003-05-27 815-619 not yet reported which blocks → AERO NORTH COMMUNICATIONS, INC. - IL 443F ROCKTON IL
2003-05-27 815-696 not yet reported which blocks → AERO NORTH COMMUNICATIONS, INC. - IL 443F ROSCOE IL
2003-05-27 815-890 not yet reported which blocks → AERO NORTH COMMUNICATIONS, INC. - IL 443F NEWMILFORD IL
2003-04-14 815-994 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → METROPCS, INC. 5562 DIXON IL
2003-03-26 815-997 0–9 XXXall 10 · 3 holders which blocks → PAETEC ITEL, LLC 829J 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.