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 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
2019-03-14 313-774 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E DETROITZN1 MI
2018-12-13 313-751 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN5 MI
2018-09-26 313-351 0–9 XXXall 10 · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E DETROITZN3 MI
2018-09-24 313-306 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN4 MI
2018-09-20 313-257 0–9 XXXwhole prefix which blocks → METROPCS, INC. 5562 DETROITZN3 MI
2018-08-31 313-816 0–9 XXXall 10 · 2 holders which blocks → AIRUS, INC. - MI 948H DETROITZN1 MI
2018-07-11 313-217 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN2 MI
2018-03-30 313-364 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN4 MI
2018-03-08 313-856 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN5 MI
2017-06-21 313-771 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN1 MI
2017-02-22 313-379 0–9 XXXall 10 · 4 holders which blocks → CLEAR RATE COMMUNICATIONS, LLC 046L DETROITZN1 MI
2017-01-12 313-426 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN1 MI
2016-11-15 313-752 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 MI
2016-08-18 313-913 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 MI
2016-07-12 313-652 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 MI
2016-06-14 313-356 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2016-04-15 313-314 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN3 MI
2016-04-15 313-636 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN4 MI
2016-04-14 313-284 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN2 MI
2016-01-13 313-509 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2015-12-24 313-251 0–9 XXXwhole prefix which blocks → ONVOY, LLCV - MI 543C DETROITZN6 MI
2015-11-25 313-788 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G DETROITZN3 MI
2015-10-01 313-992 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G DETROITZN5 MI
2015-09-28 313-765 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G DETROITZN6 MI
2015-09-17 313-666 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLCV - MI 543C DETROITZN6 MI
2015-09-03 313-797 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2015-08-20 313-775 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2015-08-12 313-800 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLCV - MI 543C DETROITZN1 MI
2015-07-23 313-398 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 MI
2015-05-21 313-290 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2015-05-21 313-979 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2015-05-12 313-635 0–9 XXXall 10 · 3 holders which blocks → COMCAST IP PHONE, LLC 318J DETROITZN4 MI
2015-05-11 313-413 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN4 MI
2015-05-11 313-747 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN4 MI
2015-04-09 313-888 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLCV - MI 543C DETROITZN1 MI
2015-02-18 313-777 0–9 XXXwhole prefix which blocks → ONVOY, LLCV - MI 543C DETROITZN3 MI
2015-01-26 313-985 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2015-01-09 313-789 0–9 XXXall 10 · 4 holders which blocks → AT&T ENTERPRISES, LLC 516C DETROITZN6 MI
2014-11-24 313-818 0–9 XXXall 10 · 6 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 MI
2014-11-24 313-936 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2014-11-07 313-699 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN4 MI
2014-11-07 313-707 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN3 MI
2014-11-07 313-855 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN4 MI
2014-10-23 313-395 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN6 MI
2014-10-23 313-403 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN6 MI
2014-10-06 313-558 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E DETROITZN6 MI
2014-09-02 313-939 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN2 MI
2014-08-08 313-266 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN6 MI
2014-08-08 313-858 0–9 XXXwhole prefix which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN6 MI
2014-07-23 313-960 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 DETROITZN1 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.