Wis. Stat. § 618.25: Requirements for unincorporated nondomestic insurers.

No nondomestic individual underwriter or syndicate may be authorized to do business in this state unless:

(1) It complies with such requirements stated in s. 618.24 as are applicable to an unincorporated insurer;

(2) It files undertakings with the commissioner to comply with legal controls and institutional practices for securing the performance of obligations that are functionally equivalent to those imposed on nondomestic insurance corporations, even if in detail the controls and practices are dissimilar; and

(3) The commissioner is satisfied that it keeps records and can supply information that will enable the commissioner to protect fully the interests of insureds, creditors and the public in this state.