Wis. Stat. § 69.17

At the end of every biweekly period, the clerk of any court which conducts divorce proceedings under ch. 767 shall forward to the state registrar, in the manner prescribed by the state registrar, a report of every divorce or annulment of marriage granted during the biweekly period. The state registrar shall require that the social security numbers of the parties to the divorce or annulment and the social security number of any child of the parties be provided.