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
2003-05-07 608-473 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC WI 7216 BELOIT WI
2003-04-18 608-843 none assigned yet which blocks → UNITED STATES CELLULAR - WI 6274 MADISON WI
2003-04-17 608-498 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 LA CROSSE WI
2003-02-05 608-554 0XXX1XXX2XXX3XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 JANESVILLE WI
2003-01-15 608-404 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 WISCONDLLS WI
2002-12-03 608-851 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 MONROE WI
2002-12-03 608-852 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 MADISON WI
2002-10-21 608-561 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 EDGERTON WI
2002-10-10 608-428 3XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 PRARIDCHIN WI
2002-08-28 608-469 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 MADISON WI
2002-08-28 608-577 none assigned yet which blocks → UNITED STATES CELLULAR - WI 6274 MADISON WI
2002-08-27 608-481 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 BELOIT WI
2002-08-26 608-449 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 JANESVILLE WI
2002-07-17 608-482 5XXX6XXX7XXX8XXX · 3 holders which blocks → UNITED STATES CELLULAR - WI 6274 DARLINGTON WI
2002-07-17 608-484 4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → UNITED STATES CELLULAR - WI 6274 GALESVILLE WI
2002-07-17 608-485 4XXX5XXX6XXX7XXX · 4 holders which blocks → UNITED STATES CELLULAR - WI 6274 BOSCOBEL WI
2002-06-20 608-628 5XXX7XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MADISON WI
2002-05-13 608-466 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 BELOIT WI
2002-05-13 608-467 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 MADISON WI
2002-04-29 608-487 8XXX9XXX which blocks → UNITED STATES CELLULAR - WI 6274 SPARTA WI
2002-03-14 608-433 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WI 5489 LA CROSSE WI
2002-03-13 608-434 none assigned yet which blocks → UNITED STATES CELLULAR - WI 6274 BARABOO WI
2002-03-12 608-649 not yet reported which blocks → TECH COM, INC. - WI 2556 RICHLD CTR WI
2002-02-15 608-443 6XXX7XXX8XXX9XXX which blocks → TDS METROCOM, LLC 520K MADISON WI
2002-01-29 608-844 2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WISCONDLLS WI
2002-01-15 608-438 none assigned yet which blocks → UNITED STATES CELLULAR - WI 6274 MADISON WI
2001-12-31 608-931 none assigned yet which blocks → UNITED STATES CELLULAR - WI 6274 JANESVILLE WI
2001-11-02 608-566 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → T-MOBILE USA, INC. 6529 PORTAGE WI
2001-11-02 608-567 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 TOMAH WI
2001-08-21 608-458 not yet reported which blocks → WISCONSIN BELL INC 9327 MADISON WI
2001-08-03 608-448 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → T-MOBILE USA, INC. 6529 BARABOO WI
2001-06-12 608-468 1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 7 holders which blocks → BRIGHTSPEED OF CENTRAL WISCONSIN, LLC 1159 FOUNTAINCY WI
2001-05-24 608-309 7XXX which blocks → BRIGHTSPEED OF CENTRAL WISCONSIN, LLC 1159 BLAIR WI
2001-05-24 608-390 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → BRIGHTSPEED OF CENTRAL WISCONSIN, LLC 1159 CENTERVL WI
2001-05-24 608-396 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → BRIGHTSPEED OF CENTRAL WISCONSIN, LLC 1159 MELROSE WI
2001-05-16 608-399 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → BRIGHTSPEED OF CENTRAL WISCONSIN, LLC 1159 HOLMEN WI
2001-05-11 608-319 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → FRONTIER NORTH INC. - WI 0886 DODGEVILLE WI
2001-05-11 608-340 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH INC. - WI 0886 BRIGGSVL WI
2001-05-11 608-350 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → FRONTIER NORTH INC. - WI 0886 MAUSTON WI
2001-05-11 608-360 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER NORTH INC. - WI 0886 LOGANVILLE WI
2001-05-11 608-370 0–9 XXXall 10 · 4 holders which blocks → UNITED STATES CELLULAR - WI 6274 SAUK CITY WI
2001-05-11 608-383 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER NORTH INC. - WI 0886 RICHLD CTR WI
2001-05-09 608-371 0–9 XXXall 10 · 7 holders which blocks → WISCONSIN BELL INC 9327 JANESVILLE WI
2001-05-08 608-442 not yet reported which blocks → TDS METROCOM, LLC 520K MADISON WI
2001-05-02 608-379 3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 6508 MOUNT HOPE WI
2001-04-18 608-307 not yet reported which blocks → SPOK, INC. 6630 JANESVILLE WI
2001-04-03 608-445 none assigned yet which blocks → UNITED STATES CELLULAR - WI 6274 MADISON WI
2001-04-01 608-724 1XXX3XXX5XXX8XXX9XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 LA CROSSE WI
2001-02-16 608-541 1XXX2XXX3XXX5XXX6XXX8XXX which blocks → PAETEC ITEL, LLC 829J STOUGHTON WI
2001-02-15 608-305 2XXX4XXX8XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J JANESVILLE 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.