Wisconsin Statutes Taxation (Ch. 70 to 79) § 76.05. Refusal or neglect to report

(1) If any company defined in s. 76.02 or its officers or agents shall refuse or neglect to make any reports required by s. 76.04 or by the department, or shall refuse or neglect to permit an inspection and examination of its records, books, accounts or papers when requested by the department, or shall refuse or neglect to appear before the department in obedience to a summons, such company shall be estopped to question or impeach the action or determination of the department except upon satisfactory proof of fraud or mistake injurious to the company.

(2) Upon a showing by the department under s. 73.16(4), no company shall be allowed in any action or proceeding to question the amount or valuation of its property as assessed by the department unless such company shall have made and filed with the department a full and complete report of the facts and information prescribed by s. 76.04 and called for by the department thereunder. If the department has not made a showing under s. 73.16(4), the company shall make a full and complete report of all facts and information mentioned in said s. 76.04 within 15 days after notice by mail of the amount of the assessment of the property of such company, and shall appear before the department at a time designated by it and make a full disclosure of all property liable to assessment and taxation under this subchapter and show the full value of such property to the satisfaction of the department.