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 586
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 132
MICHIGAN BELL TEL CO 100
NEW CINGULAR WIRELESS PCS, LLC - IL 60
OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 43
AMERICAN MESSAGING SERVICES, LLC 27
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
2014-05-16 586-320 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2014-05-16 586-659 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2014-04-17 586-636 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G RICHMOND MI
2014-03-27 586-217 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLCV - MI 543C ROSEVILLE MI
2014-03-05 586-221 0–9 XXXall 10 · 6 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J MT CLEMENS MI
2014-02-28 586-225 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E CENTERLINE MI
2013-09-26 586-205 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-09-26 586-348 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-09-26 586-428 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-09-13 586-342 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-08-28 586-324 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-08-28 586-494 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-08-14 586-249 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-08-14 586-388 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-06-14 586-522 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MT CLEMENS MI
2013-05-15 586-210 0–9 XXXall 10 · 6 holders which blocks → FIRST COMMUNICATIONS, LLC 460K NEWBALTIMR MI
2013-04-10 586-200 0–9 XXXall 10 · 7 holders which blocks → COMCAST IP PHONE, LLC 318J ROSEVILLE MI
2013-01-24 586-208 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-24 586-233 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-24 586-424 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-24 586-515 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-24 586-689 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-24 586-787 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-24 586-789 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-21 586-229 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MT CLEMENS MI
2013-01-16 586-332 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2013-01-11 586-289 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MT CLEMENS MI
2012-07-13 586-343 0–9 XXXall 10 · 6 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ROSEVILLE MI
2012-06-12 586-315 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E NEW HAVEN MI
2011-07-15 586-359 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 ROSEVILLE MI
2010-11-10 586-533 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 ROSEVILLE MI
2010-10-21 586-277 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 NEW HAVEN MI
2010-08-06 586-265 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MT CLEMENS MI
2010-07-12 586-335 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 ROSEVILLE MI
2009-12-16 586-404 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 ROSEVILLE MI
2009-03-05 586-209 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 ROSEVILLE MI
2008-11-03 586-282 0–9 XXXwhole prefix which blocks → MICHIGAN BELL TEL CO 9323 CENTERLINE MI
2008-09-18 586-298 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 ROSEVILLE MI
2008-08-26 586-441 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 ROSEVILLE MI
2008-06-19 586-231 0–9 XXXall 10 · 5 holders which blocks → COMCAST IP PHONE, LLC 318J MT CLEMENS MI
2007-12-05 586-239 0–9 XXXall 10 · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 MT CLEMENS MI
2007-07-10 586-275 0–9 XXXall 10 · 6 holders which blocks → COMCAST IP PHONE, LLC 318J WARREN MI
2006-10-10 586-329 0–9 XXXall 10 · 6 holders which blocks → METROPCS, INC. 5562 MT CLEMENS MI
2006-05-23 586-248 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → CYNERGYCOMM.NET, INC. - MI 9245 RICHMOND MI
2006-03-20 586-745 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → AT&T ENTERPRISES, LLC 516C WASHINGTON MI
2006-03-07 586-244 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEW HAVEN MI
2006-03-06 586-232 0–9 XXXall 10 · 7 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E WASHINGTON MI
2005-08-18 586-744 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 WARREN MI
2005-03-14 586-222 0–9 XXXall 10 · 2 holders which blocks → PAETEC ITEL, LLC 829J ROSEVILLE MI
2004-06-09 586-218 0–9 XXXall 10 · 8 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ROSEVILLE MI

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.