Wis. Stat. § 223.10: Organizations as fiduciaries.

Except as provided in s. 54.15 (7), no court or probate registrar in this state may appoint or issue letters to any corporation, limited liability company, association, partnership or business trust as trustee, personal representative, guardian, conservator, assignee, receiver, or in any other fiduciary capacity unless such corporation, limited liability company, association, partnership or business trust is subject to regulation and examination under s. 223.105, or is a national bank, state or federal savings and loan association, state or federal savings bank or federal credit union with authority to exercise such powers, or is a foreign corporation operating under s. 223.12.