Wis. Stat. § 610.11: Qualified insurers.

No person may do an insurance business as defined in s. 618.02 (2) on the person’s own account in this state, either in person, or through agents or brokers, or through the mail or any other method of communication, except:

(1) An insurer authorized to do business in this state, within the limits of its certificate of authority; or

(2) An insurer doing business under s. 618.41.