Recent prefix assignments

1 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, last 30 days — NPA 517

CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 1

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
2013-03-08	517-295	0–9 XXXall 10 · 4 holders which blocks →	BANDWIDTH.COM CLEC, LLC - MI	991E	HOWELL	MI
2012-04-03	517-343	0–9 XXXall 10 · 6 holders which blocks →	WOW! INTERNET, CABLE AND PHONE	961J	ALBION	MI
2012-03-12	517-258	0–9 XXXall 10 · 4 holders which blocks →	BANDWIDTH.COM CLEC, LLC - MI	991E	HOWELL	MI
2011-12-07	517-836	0–9 XXXall 10 · 7 holders which blocks →	CLEAR RATE COMMUNICATIONS, LLC	046L	EATON RPD	MI
2011-08-11	517-284	0–9 XXXwhole prefix which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
2010-12-23	517-715	0–9 XXXall 10 · 7 holders which blocks →	ONVOY, LLCV - MI	543C	FOWLERVL	MI
2010-12-07	517-235	0–9 XXXall 10 · 4 holders which blocks →	AT&T ENTERPRISES, LLC	516C	DIMONDALE	MI
2010-11-10	517-662	0–9 XXXall 10 · 5 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	6003	ADRIAN	MI
2010-08-06	517-798	0–9 XXXall 10 · 4 holders which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	HOWELL	MI
2010-08-05	517-528	0–9 XXXall 10 · 2 holders which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	LANSING	MI
2010-05-26	517-412	0–9 XXXall 10 · 4 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	GRANDLEDGE	MI
2010-04-02	517-366	0–9 XXXall 10 · 7 holders which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	ADRIAN	MI
2010-04-02	517-489	0–9 XXXall 10 · 5 holders which blocks →	ONVOY, LLCV - MI	543C	LANSING	MI
2010-03-29	517-240	0–9 XXXall 10 · 2 holders which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	JACKSON	MI
2010-01-14	517-215	0–9 XXXall 10 · 3 holders which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	ADRIAN	MI
2009-12-22	517-465	0XXX1XXX3XXX4XXX7XXX8XXX9XXX · 6 holders which blocks →	AT&T ENTERPRISES, LLC	516C	ALBION	MI
2009-12-08	517-395	0–9 XXXall 10 · 5 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	6003	JACKSON	MI
2009-11-17	517-459	0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MI	6120	PARMA	MI
2009-11-16	517-731	0–9 XXXall 10 · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MI	6120	GRANDLEDGE	MI
2009-05-04	517-209	0–9 XXXall 10 · 4 holders which blocks →	BANDWIDTH.COM CLEC, LLC - MI	991E	HOLT	MI
2009-02-06	517-348	0–9 XXXall 10 · 4 holders which blocks →	ONVOY, LLCV - MI	543C	LANSING	MI
2008-10-28	517-616	0–9 XXXall 10 · 4 holders which blocks →	ONVOY, LLCV - MI	543C	DIMONDALE	MI
2008-09-16	517-305	0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 5 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MI	6120	CLARKLAKE	MI
2008-09-02	517-742	0–9 XXXall 10 · 4 holders which blocks →	AT&T ENTERPRISES, LLC	516C	HOLT	MI
2008-04-10	517-574	0–9 XXXall 10 · 4 holders which blocks →	CLEAR RATE COMMUNICATIONS, LLC	046L	LANSING	MI
2008-03-10	517-515	0–9 XXXall 10 · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	LANSING	MI
2008-03-03	517-894	0–9 XXXwhole prefix which blocks →	METROPCS, INC.	5562	LANSING	MI
2008-02-04	517-883	0–9 XXXall 10 · 9 holders which blocks →	FIRST COMMUNICATIONS, LLC	460K	MASON	MI
2007-10-08	517-975	0–9 XXXall 10 · 3 holders which blocks →	PAETEC ITEL, LLC	829J	LANSING	MI
2007-10-02	517-901	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 5 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	READING	MI
2007-08-07	517-962	0–9 XXXall 10 · 6 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	770E	JACKSON	MI
2007-07-03	517-802	0–9 XXXall 10 · 3 holders which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
2007-06-18	517-939	0XXX1XXX3XXX5XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MI	6120	QUINCY	MI
2007-04-12	517-408	0–9 XXXall 10 · 3 holders which blocks →	COMCAST IP PHONE, LLC	318J	DIMONDALE	MI
2007-01-04	517-924	0XXX1XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks →	CHARTER IP ENABLED SERVICES, LLC	792K	COLDWATER	MI
2006-08-16	517-977	0–9 XXXall 10 · 3 holders which blocks →	COMCAST IP PHONE, LLC	318J	LANSING	MI
2006-07-19	517-708	0–9 XXXall 10 · 6 holders which blocks →	CYNERGYCOMM.NET, INC. - MI	9245	LANSING	MI
2006-05-24	517-624	0–9 XXXall 10 · 5 holders which blocks →	ONVOY, LLCV - MI	543C	DE WITT	MI
2006-03-02	517-709	0–9 XXXall 10 · 7 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI	7157	HOLT	MI
2006-02-09	517-966	0–9 XXXwhole prefix which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI	7157	DIMONDALE	MI
2006-02-01	517-920	0–9 XXXall 10 · 4 holders which blocks →	TELNET WORLDWIDE, INC.	817J	ADRIAN	MI
2006-01-27	517-968	0–9 XXXall 10 · 2 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI	7157	DANSVILLE	MI
2006-01-17	517-910	0–9 XXXall 10 · 7 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MI	6120	ONONDAGA	MI
2006-01-12	517-889	0–9 XXXall 10 · 7 holders which blocks →	PAETEC ITEL, LLC	829J	HOLT	MI
2006-01-12	517-969	0–9 XXXall 10 · 5 holders which blocks →	PAETEC ITEL, LLC	829J	MASON	MI
2005-12-07	517-701	0–9 XXXall 10 · 6 holders which blocks →	123.NET, LLC	2550	CLINTON	MI
2005-11-28	517-878	0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MI	6120	LESLIE	MI
2005-10-17	517-600	0–9 XXXwhole prefix which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI	7157	DIMONDALE	MI
2005-09-22	517-755	0–9 XXXall 10 · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	LANSING	MI
2005-09-15	517-222	0–9 XXXall 10 · 3 holders which blocks →	MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI	7157	DANSVILLE	MI

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.