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 608
WISCONSIN BELL INC 80
UNITED STATES CELLULAR - WI 76
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 54
FRONTIER NORTH INC. - WI 53
ONVOY, LLC - WI 50
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
2018-11-21 608-590 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - WI 225C MADISON WI
2018-10-31 608-901 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 JANESVILLE WI
2018-10-08 608-540 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOLMEN WI
2018-09-27 608-889 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF WISCONSIN, LLC - WI 227F STOUGHTON WI
2018-07-24 608-597 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - WI 225C MCFARLAND WI
2018-07-23 608-470 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - WI 225C EDGERTON WI
2018-06-25 608-802 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC WI 7216 BELOIT WI
2018-03-23 608-982 0–9 XXXall 10 · 5 holders which blocks → VONAGE AMERICA LLC 197D MADISON WI
2017-10-19 608-507 1XXX7XXX · 2 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J BOAZ WI
2017-10-19 608-595 0XXX2XXX5XXX7XXX · 3 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J BLUE RIVER WI
2017-10-19 608-887 0XXX2XXX5XXX7XXX8XXX · 4 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J GAYS MILLS WI
2017-10-19 608-955 2XXX5XXX7XXX9XXX · 4 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J SOLDIRSGRV WI
2017-10-09 608-517 0XXX1XXX2XXX3XXX4XXX6XXX7XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 FENNIMORE WI
2017-10-09 608-569 2XXX7XXX · 2 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J BAGLEY WI
2017-10-09 608-859 6XXX7XXX9XXX · 3 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J BEETOWN WI
2017-10-04 608-653 0–9 XXXall 10 · 6 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J VERONA WI
2017-10-04 608-899 0XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J WOODMAN WI
2017-09-28 608-400 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - WI 225C MADISON WI
2017-09-28 608-708 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 DEERFIELD WI
2017-09-28 608-912 0–9 XXXall 10 · 7 holders which blocks → BANDWIDTH.COM CLEC, LLC - WI 007F DE FOREST WI
2017-09-11 608-733 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MADISON WI
2017-08-08 608-925 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SOUTHWAYNE WI
2017-07-06 608-510 0XXX1XXX3XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GRATIOT WI
2017-04-04 608-530 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JANESVILLE WI
2017-04-03 608-693 0XXX1XXX2XXX3XXX6XXX7XXX9XXX · 6 holders which blocks → UNITED STATES CELLULAR - WI 6274 WESTBY WI
2017-03-06 608-731 2XXX3XXX · 2 holders which blocks → ONVOY, LLC - WI 225C WEST SALEM WI
2016-12-05 608-405 0–9 XXXall 10 · 7 holders which blocks → TELNYX LLC 073H MADISON WI
2016-08-23 608-460 0–9 XXXall 10 · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SAUK CITY WI
2016-08-01 608-640 0–9 XXXall 10 · 5 holders which blocks → UNITED STATES CELLULAR - WI 6274 MADISON WI
2016-06-09 608-720 0–9 XXXall 10 · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC WI 7216 MADISON WI
2016-06-08 608-480 0–9 XXXall 10 · 4 holders which blocks → UNITED STATES CELLULAR - WI 6274 STOUGHTON WI
2016-04-19 608-898 0–9 XXXall 10 · 7 holders which blocks → METROPCS, INC. 5562 JANESVILLE WI
2016-04-07 608-615 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LA CROSSE WI
2016-03-23 608-384 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC WI 7216 MINERAL PT WI
2016-01-25 608-591 0–9 XXXall 10 · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC WI 7216 LODI WI
2016-01-22 608-975 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC WI 7216 BELLEVILLE WI
2016-01-13 608-885 0–9 XXXall 10 · 7 holders which blocks → UNITED STATES CELLULAR - WI 6274 LANCASTER WI
2015-11-17 608-800 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - WI 225C MADISON WI
2015-11-11 608-581 0–9 XXXall 10 · 7 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 BARABOO WI
2015-08-17 608-888 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - WI 225C MADISON WI
2015-07-31 608-598 0–9 XXXall 10 · 4 holders which blocks → UNITED STATES CELLULAR - WI 6274 MADISON WI
2015-04-28 608-977 0–9 XXXall 10 · 3 holders which blocks → WISCONSIN BELL INC 9327 MADISON WI
2015-02-18 608-999 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - WI 225C MADISON WI
2015-02-17 608-909 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - WI 007F OREGON WI
2015-01-26 608-688 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - WI 007F COTTAGEGRV WI
2014-12-23 608-747 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 7 holders which blocks → ONVOY, LLC - WI 225C MAUSTON WI
2014-12-04 608-496 0XXX1XXX4XXX8XXX9XXX · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - WI 007F CAMBRIDGE WI
2014-11-25 608-699 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 CAMBRIDGE WI
2014-10-10 608-571 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF WISCONSIN, LLC - WI 227F MADISON WI
2014-10-06 608-440 0–9 XXXall 10 · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC WI 7216 MADISON WI

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.