NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 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, all time — NPA 313
MICHIGAN BELL TEL CO 244
OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 141
NEW CINGULAR WIRELESS PCS, LLC - IL 95
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 54
BANDWIDTH.COM CLEC, LLC - MI 28
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
2013-12-03 313-349 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2013-12-03 313-723 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN4 MI
2013-11-27 313-502 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 MI
2013-10-24 313-246 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN5 MI
2013-10-24 313-545 0–9 XXXwhole prefix which blocks → MICHIGAN BELL TEL CO 9323 DETROITZN1 MI
2013-09-19 313-307 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLCV - MI 543C DETROITZN4 MI
2013-06-26 313-315 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2013-06-26 313-773 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2013-06-26 313-812 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2013-06-12 313-265 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 MI
2013-05-29 313-214 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2013-05-29 313-326 0–9 XXXall 10 · 6 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2013-05-28 313-264 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2013-05-28 313-327 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2013-05-28 313-367 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN4 MI
2013-05-28 313-374 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN6 MI
2013-05-17 313-472 0–9 XXXall 10 · 3 holders which blocks → AT&T ENTERPRISES, LLC 516C DETROITZN5 MI
2013-05-13 313-725 0–9 XXXall 10 · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 DETROITZN1 MI
2013-03-11 313-209 0–9 XXXall 10 · 2 holders which blocks → PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G DETROITZN1 MI
2012-12-26 313-296 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 DETROITZN5 MI
2012-10-19 313-603 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2012-09-28 313-236 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 DETROITZN5 MI
2012-09-28 313-495 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 DETROITZN5 MI
2012-08-29 313-353 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2012-08-29 313-428 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2012-07-12 313-229 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2012-07-12 313-352 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2012-06-22 313-782 0–9 XXXall 10 · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 DETROITZN1 MI
2012-02-08 313-241 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLCV - MI 543C DETROITZN4 MI
2011-10-11 313-338 0–9 XXXall 10 · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 DETROITZN1 MI
2011-10-06 313-649 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2011-08-31 313-287 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2011-08-31 313-713 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2011-08-31 313-844 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2011-05-23 313-757 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN6 MI
2011-01-07 313-744 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN4 MI
2010-12-09 313-448 0–9 XXXall 10 · 2 holders which blocks → MICHIGAN BELL TEL CO 9323 DETROITZN1 MI
2010-11-23 313-455 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2010-11-11 313-626 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN2 MI
2010-09-13 313-829 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2010-09-13 313-953 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2010-07-28 313-932 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2010-07-07 313-848 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN5 MI
2010-04-02 313-462 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLCV - MI 543C DETROITZN1 MI
2010-03-19 313-437 0–9 XXXall 10 · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E DETROITZN4 MI
2010-02-17 313-451 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN6 MI
2009-10-20 313-358 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN6 MI
2009-10-16 313-312 0–9 XXXall 10 · 3 holders which blocks → PAETEC ITEL, LLC 829J DETROITZN3 MI
2009-10-06 313-373 0–9 XXXwhole prefix which blocks → MICHIGAN BELL TEL CO 9323 DETROITZN1 MI
2009-04-16 313-444 0–9 XXXall 10 · 2 holders which blocks → PAETEC ITEL, LLC 829J DETROITZN2 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.