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

Recent NPA-NXX prefix assignments
Assigned	NPA-NXX	Thousands-blocks taken (last-4 opening)	Code holder	OCN	Rate center	State
—	815-504	not yet reported which blocks →	FIRST COMMUNICATIONS, LLC	460K	GARDNER	IL
—	815-505	not yet reported which blocks →	T-MOBILE USA, INC.	6529	ROCKFORD	IL
—	815-509	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	ROCKFORD	IL
—	815-511	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	IL
—	815-512	not yet reported which blocks →	FIRST COMMUNICATIONS, LLC	460K	LOCKPORT	IL
—	815-519	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	ROCKFORD	IL
—	815-520	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL	6333	ROCKFORD	IL
—	815-521	6XXX which blocks →	ILLINOIS BELL TEL CO	9329	MINOOKA	IL
—	815-522	0XXX1XXX4XXX5XXX7XXX8XXX · 5 holders which blocks →	FRONTIER NORTH, INC. - IL	1036	KIRKLAND	IL
—	815-523	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - IL	7136	KANKAKEE	IL
—	815-524	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - IL	7136	LOCKPORT	IL
—	815-525	not yet reported which blocks →	TDS METROCOM, LLC	520K	SO BELOIT	IL
—	815-526	0XXX1XXX2XXX3XXX5XXX7XXX8XXX · 6 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - IL	7136	CRYSTAL LK	IL
—	815-527	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - IL	7136	WOODSTOCK	IL
—	815-528	0XXX1XXX2XXX3XXX4XXX5XXX8XXX · 3 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - IL	7136	MCHENRY	IL
—	815-529	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL	6333	WOODSTOCK	IL
—	815-530	0–9 XXXall 10 · 3 holders which blocks →	T-MOBILE USA, INC.	6529	JOLIET	IL
—	815-531	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - IL	7136	JOLIET	IL
—	815-532	not yet reported which blocks →	SPOK, INC.	6630	MORRIS	IL
—	815-533	not yet reported which blocks →	INDIANA PAGING NETWORK, INC.	6795	LA GRANGE	IL
—	815-534	0–9 XXXall 10 · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - IL	6115	FRANKFORT	IL
—	815-535	none assigned yet which blocks →	ILLINOIS BELL TEL CO	9329	STERLING	IL
—	815-536	not yet reported which blocks →	SPOK, INC.	6630	LA GRANGE	IL
—	815-537	not yet reported which blocks →	CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL	1183	PROPHETSTN	IL
—	815-538	8XXX9XXX · 2 holders which blocks →	FRONTIER NORTH, INC. - IL	1015	MENDOTA	IL
—	815-539	4XXX8XXX · 2 holders which blocks →	FRONTIER NORTH, INC. - IL	1015	MENDOTA	IL
—	815-540	none assigned yet which blocks →	T-MOBILE USA, INC.	6529	ROCKFORD	IL
—	815-541	none assigned yet which blocks →	UNITED STATES CELLULAR - IL	6265	FREEPORT	IL
—	815-542	2XXX3XXX4XXX5XXX · 3 holders which blocks →	CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL	1183	THOMAS	IL
—	815-543	none assigned yet which blocks →	UNITED STATES CELLULAR - IL	6265	ROCKFORD	IL
—	815-544	not yet reported which blocks →	FRONTIER NORTH, INC. - IL	1015	BELVIDERE	IL
—	815-545	not yet reported which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	JOLIET	IL
—	815-546	not yet reported which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	JOLIET	IL
—	815-547	not yet reported which blocks →	FRONTIER NORTH, INC. - IL	1015	BELVIDERE	IL
—	815-548	not yet reported which blocks →	ILLINOIS BELL TEL CO	9329	STERLING	IL
—	815-549	8XXX which blocks →	T-MOBILE USA, INC.	6529	KANKAKEE	IL
—	815-550	none assigned yet which blocks →	LEVEL 3 COMMUNICATIONS, LLC - IL	6115	GRANT PARK	IL
—	815-554	0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks →	MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL	846F	E DUBUQUE	IL
—	815-555	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	DIR ASST	IL
—	815-557	2XXX which blocks →	METROPCS, INC.	5562	JOLIET	IL
—	815-558	4XXX6XXX7XXX9XXX · 2 holders which blocks →	UNITED STATES CELLULAR - IL	6265	ROCKFORD	IL
—	815-559	0XXX1XXX2XXX5XXX7XXX8XXX9XXX · 5 holders which blocks →	VOIP INNOVATIONS, LLC	597F	CHENOA	IL
—	815-561	4XXX5XXX6XXX7XXX · 4 holders which blocks →	FRONTIER NORTH, INC. - IL	1036	ROCHELLE	IL
—	815-562	not yet reported which blocks →	FRONTIER NORTH, INC. - IL	1036	ROCHELLE	IL
—	815-563	0XXX1XXX3XXX5XXX6XXX8XXX · 5 holders which blocks →	FRONTIER NORTH, INC. - IL	1036	CEDARVILLE	IL
—	815-564	2XXX3XXX · 2 holders which blocks →	ILLINOIS BELL TEL CO	9329	STERLING	IL
—	815-565	1XXX2XXX6XXX7XXX · 4 holders which blocks →	MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL	846F	SAVANNA	IL
—	815-567	1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	FRONTIER NORTH, INC. - IL	1015	CAMPUS	IL
—	815-568	9XXX which blocks →	ILLINOIS BELL TEL CO	9329	MARENGO	IL
—	815-569	0XXX3XXX4XXX5XXX6XXX8XXX · 4 holders which blocks →	FRONTIER NORTH, INC. - IL	1015	CAPRON	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.