Minn. Stat. § 471.382: CREDIT CARDS.

A city council or town board may authorize the use of a credit card by any city or town officer or employee otherwise authorized to make a purchase on behalf of the city or town. If a city or town officer or employee makes or directs a purchase by credit card that is not approved by the city council or town board, the officer or employee is personally liable for the amount of the purchase. A purchase by credit card must otherwise comply with all statutes, rules, or city or town policy applicable to city or town purchases.