NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

1 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, 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
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2021-04-08 517-770 0–9 XXXall 10 · 4 holders which blocks → COMMIO, LLC 939H LANSING MI
2021-03-31 517-786 0–9 XXXall 10 · 6 holders which blocks → FRACTEL, LLC 965H CHARLOTTE MI
2021-03-19 517-291 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → STRATUS NETWORKS 495J ADRIAN MI
2021-02-22 517-855 0–9 XXXall 10 · 4 holders which blocks → TERRA NOVA TELECOM INC. 145J LANSING MI
2021-01-28 517-328 0XXX1XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → IP HORIZON LLC 515J LANSING MI
2021-01-19 517-280 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ADRIAN MI
2020-10-26 517-271 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLCV - MI 543C NASHVILLE MI
2020-10-20 517-261 0XXX1XXX2XXX3XXX4XXX5XXX6XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 GRANDLEDGE MI
2020-06-25 517-216 0–9 XXXall 10 · 4 holders which blocks → CSC WIRELESS, LLC 425J LANSING MI
2020-02-19 517-842 2XXX4XXX5XXX8XXX · 4 holders which blocks → FRACTEL, LLC 965H GRASS LAKE MI
2019-11-25 517-758 0–9 XXXall 10 · 3 holders which blocks → FRACTEL, LLC 965H HOLT MI
2019-11-22 517-356 0–9 XXXall 10 · 2 holders which blocks → FRACTEL, LLC 965H LANSING MI
2019-10-29 517-400 0–9 XXXall 10 · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H LANSING MI
2019-10-10 517-300 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLCV - MI 543C ONSTED MI
2019-09-12 517-800 0–9 XXXall 10 · 3 holders which blocks → FRACTEL, LLC 965H JACKSON MI
2019-08-01 517-246 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G LANSING MI
2019-06-17 517-329 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 2 holders which blocks → VOIP INNOVATIONS, LLC 597F LANSING MI
2019-05-14 517-247 0–9 XXXall 10 · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E JACKSON MI
2019-04-22 517-928 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MASON MI
2019-01-23 517-428 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 FOWLERVL MI
2018-09-25 517-500 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLCV - MI 543C SUNFIELD MI
2018-08-22 517-550 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → ONVOY, LLCV - MI 543C DIMONDALE MI
2018-03-09 517-730 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → VONAGE AMERICA LLC 197D LANSING MI
2017-11-21 517-666 0XXX1XXX2XXX3XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → ONVOY, LLCV - MI 543C GRANDLEDGE MI
2017-10-24 517-722 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7157 MASON MI
2017-10-11 517-619 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E LANSING MI
2017-07-26 517-273 0–9 XXXall 10 · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E HOWELL MI
2017-04-26 517-257 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 JACKSON MI
2017-03-30 517-275 0–9 XXXall 10 · 5 holders which blocks → WIRETAP TELECOM, LLC. 733J LANSING MI
2017-03-08 517-249 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LANSING MI
2016-11-08 517-234 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOWELL MI
2016-04-12 517-221 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOLT MI
2016-04-12 517-867 0–9 XXXall 10 · 3 holders which blocks → CLEAR RATE COMMUNICATIONS, LLC 046L JACKSON MI
2016-03-08 517-201 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLCV - MI 543C LESLIE MI
2016-03-08 517-210 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLCV - MI 543C POTTERVL MI
2015-11-16 517-225 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOWELL MI
2015-10-14 517-220 0–9 XXXall 10 · 5 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J LANSING MI
2015-09-17 517-245 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 FOWLERVL MI
2015-08-18 517-777 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLCV - MI 543C HOLT MI
2015-08-18 517-888 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLCV - MI 543C JACKSON MI
2015-04-23 517-239 0XXX1XXX3XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - MI 0695 DE WITT MI
2015-04-23 517-312 0–9 XXXall 10 · 5 holders which blocks → FRONTIER NORTH, INC. - MI 0695 ADRIAN MI
2015-03-13 517-539 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 JACKSON MI
2014-07-25 517-940 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LANSING MI
2014-05-30 517-457 0XXX1XXX2XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G TIPTON MI
2014-04-17 517-205 0–9 XXXwhole prefix which blocks → MICHIGAN BELL TEL CO 9323 JACKSON MI
2014-03-13 517-208 0–9 XXXall 10 · 4 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J BRITTON MI
2014-03-12 517-429 0–9 XXXall 10 · 5 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J HUDSON MI
2013-10-04 517-435 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 JACKSON MI
2013-04-19 517-253 0–9 XXXall 10 · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 LANSING 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.