Wis. Stat. § 301.10: Purchases, bills, audits, payments.

Unless otherwise provided by law, no bills may be incurred in the management of the institutions nor be paid until they have been audited by the department of corrections under the supervision of the department of administration. All payments shall be made on the warrant of the department of administration drawn in accordance with the certificate of the proper designated officer of the department of corrections. All claims and accounts, before being certified to the department of administration by the department of corrections, shall be verified and approved as provided in s. 16.53.