Wis. Stat. § 632.36: Accident in the course of business or employment.

(1) Rate and other terms. An insurer may increase or charge a higher rate for a motor vehicle liability insurance policy issued or renewed on or after April 16, 1982, on the basis of an accident which occurs while the insured is operating a motor vehicle in the course of the insured’s business or employment, only if the policy covers the insured for liability arising in the course of the insured’s business or employment. An insurer may issue or renew a motor vehicle liability insurance policy on or after November 1, 1989, on terms that are less favorable to the insured than would otherwise be offered, including but not limited to the rate, because of an accident which occurs while the insured is operating a motor vehicle in the course of the insured’s business or employment, only if the policy covers the insured for liability arising in the course of the insured’s business or employment.

(2) Cancellation or nonrenewal. An insurer may cancel a motor vehicle liability insurance policy that is issued or renewed on or after November 1, 1989, or refuse to renew a motor vehicle liability insurance policy on or after November 1, 1989, on the basis of an accident which occurs while the insured is operating a motor vehicle in the course of the insured’s business or employment, only if the policy covers the insured for liability arising in the course of the insured’s business or employment.