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
—	517-372	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-373	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-374	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-376	0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 5 holders which blocks →	COMCAST IP PHONE, LLC	318J	HOWELL	MI
—	517-377	2XXX5XXX6XXX7XXX · 2 holders which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-381	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-383	not yet reported which blocks →	FRONTIER COMMUNICATIONS OF MICHIGAN, INC.	4417	PRATTVILLE	MI
—	517-388	7XXX8XXX9XXX which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	6003	LANSING	MI
—	517-390	not yet reported which blocks →	AMERICAN MESSAGING SERVICES, LLC	9748	JACKSON	MI
—	517-391	0XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	LANSING	MI
—	517-392	0–9 XXXall 10 · 3 holders which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	JACKSON	MI
—	517-393	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-394	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-398	7XXX8XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	HILLSDALE	MI
—	517-401	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	MORENCI	MI
—	517-402	not yet reported which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	LANSING	MI
—	517-403	none assigned yet which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	ADRIAN	MI
—	517-404	none assigned yet which blocks →	METROPCS, INC.	5562	HOWELL	MI
—	517-407	not yet reported which blocks →	AMERICAN MESSAGING SERVICES, LLC	9748	JONESVILLE	MI
—	517-409	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks →	TWILIO INTERNATIONAL, INC.	506J	BLISSFIELD	MI
—	517-410	none assigned yet which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	LANSING	MI
—	517-411	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MI
—	517-414	none assigned yet which blocks →	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	2964	JACKSON	MI
—	517-417	not yet reported which blocks →	TC3 TELECOM, INC. - MI	3459	ADRIAN	MI
—	517-418	2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	HOMER	MI
—	517-420	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	6003	LANSING	MI
—	517-423	not yet reported which blocks →	FRONTIER NORTH, INC. - MI	0695	TECUMSEH	MI
—	517-424	2XXX which blocks →	FRONTIER NORTH, INC. - MI	0695	TECUMSEH	MI
—	517-425	5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	6003	HILLSDALE	MI
—	517-431	0XXX1XXX4XXX5XXX6XXX7XXX9XXX · 7 holders which blocks →	FRONTIER NORTH, INC. - MI	0695	TIPTON	MI
—	517-432	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	LANSING	MI
—	517-436	0XXX1XXX2XXX4XXX5XXX8XXX · 5 holders which blocks →	SAND CREEK TEL. CO.	0725	SAND CREEK	MI
—	517-437	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	HILLSDALE	MI
—	517-438	5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	6003	ADRIAN	MI
—	517-439	not yet reported which blocks →	MICHIGAN BELL TEL CO	9323	HILLSDALE	MI
—	517-441	0–9 XXXall 10 · 7 holders which blocks →	LEVEL 3 COMMUNICATIONS, LLC - MI	6120	EATON RPD	MI
—	517-442	1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	ADRIAN	MI
—	517-443	2XXX4XXX7XXX8XXX9XXX · 4 holders which blocks →	OGDEN TEL. CO.	0714	OGDEN CTR	MI
—	517-445	3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks →	COMMUNICATIONS CORP. OF MI	0672	CLAYTON	MI
—	517-446	0XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks →	DEERFIELD FARMERS' TELEPHONE COMPANY - MI	558A	ONSTED	MI
—	517-447	0XXX1XXX2XXX6XXX9XXX · 3 holders which blocks →	DEERFIELD FARMERS TEL. CO.	0691	DEERFIELD	MI
—	517-448	0XXX1XXX9XXX · 3 holders which blocks →	FRONTIER NORTH, INC. - MI	0695	HUDSON	MI
—	517-449	not yet reported which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	6003	LANSING	MI
—	517-451	0XXX1XXX3XXX6XXX7XXX · 5 holders which blocks →	FRONTIER NORTH, INC. - MI	0695	BRITTON	MI
—	517-456	0XXX3XXX5XXX · 3 holders which blocks →	FRONTIER NORTH, INC. - MI	0695	CLINTON	MI
—	517-458	0XXX3XXX4XXX5XXX8XXX9XXX · 5 holders which blocks →	FRONTIER MIDSTATES, INC. - MI	0681	MORENCI	MI
—	517-464	not yet reported which blocks →	AMERICAN MESSAGING SERVICES, LLC	9748	JACKSON	MI
—	517-467	1XXX5XXX · 2 holders which blocks →	FRONTIER COMMUNICATIONS OF MICHIGAN, INC.	4417	ONSTED	MI
—	517-468	5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	SHIAWASSEE TEL. CO.	0726	BELL OAK	MI
—	517-470	not yet reported which blocks →	TC3 TELECOM, INC. - MI	3459	TECUMSEH	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.