State Tax Day - Current, S.25, Wisconsin—Personal Income Tax: Amended Return Filed Too Late, (Apr 23, 2026)

Petitioners owned property damaged by a storm in 2017. They filed their 2017 income tax return on April 14, 2018, but did not include any claim of casualty and/or loss. Petitioners filed an amended 2017 income tax return in July of 2024, seeking a refund related to the 2017 casualty loss from weather damage to their home. In this case, the Commission lacked jurisdiction over the Petitioner for Review because the claim for refund was untimely. The Department's denial of the Petition for Redetermination was affirmed, and the Petition for Review was dismissed. An amended return must be filed within 4 years of the unextended due date of the return for which amendment is sought. The due date for the amended return here was due no later than April 17, 2022. While it was unfortunate that filing deadlines were not changed during the COVID-19 pandemic, and that it was difficult for the petitioners to get repairs completed and obtain documentation necessary for the refund, the Commission is bound by the statutory timelines as they are written.

Williamson v. Wisconsin Department of Revenue, Wisconsin Tax Appeals Commission, No. 25-I-071, March 26, 2026, ¶402-616