Wis. Stat. § 779.04

All claims for liens and right to recover therefor under this subchapter are assignable. Notice in writing of such assignment may be served upon the owner of the property affected and all payments made by the owner before service of such notice shall discharge the debt to the amount paid. The assignee may file petitions for such liens and may bring an action in the assignee’s name to enforce the same, subject to the limitations in s. 779.01 (5).