Wisconsin Statutes Trade Regulations (Ch. 125 to 139) § 139.85. Interest and penalties

(1) The interest and penalties under s. 139.44(2) to (7) and (9) to (12) apply to this subchapter. In addition, a person who violates s. 139.82(8) may be fined not more than $10,000 or imprisoned for not more than 9 months or both.

(2) If a person fails to file any return required under s. 139.77(1) by the due date, unless the person shows that that failure was due to reasonable cause and not due to neglect, the department shall add to the amount of tax required to be shown on that return 5 percent of the amount of the tax if the failure is for not more than one month and an additional 5 percent of the tax for each additional month or fraction of a month during which the failure continues, but not more than 25 percent of the tax. For purposes of this subsection, the amount of tax required to be shown on the return shall be reduced by the amount of tax that is paid on or before the due date and by the amount of any credit against the tax that may be claimed on the return.