Wisconsin Statutes Employment, Compensation and Mining (Ch. 101 to 109) § 108.11. Agreement to contribute by employees void

(1) No agreement by an employee or by employees to pay any portion of the contributions or payments in lieu of contributions required under this chapter from employers shall be valid. No employer shall make a deduction for such purpose from wages. Any employee claiming a violation of this provision may, to recover wage deductions wrongfully made, have recourse to the method set up in s. 108.09 for settling disputed benefit claims.

(2) But nothing in this chapter shall affect the validity of voluntary arrangements whereby employees freely agree to make contributions to a fund for the purpose of securing unemployment compensation additional to the benefits provided in this chapter.