The primary difference is that a circuit court handles a wide variety of legal claims made under state law and a municipal court only handles prosecution of local ordinance violations.
Municipal courts only hear cases in which a city alleges that an individual violated an ordinance. The primary penalty is a forfeiture, which is just the legal word for a money payment. Although a municipal judge can order a defendant to serve time in jail for non-payment of a forfeiture, that judge cannot directly order jail time as a penalty. A municipal court only exists when a city creates one and operates under the rules found in Chapter 800 of the Wisconsin Statutes.
Circuit courts hear state claims on a wide variety of topics, including contracts, real estate, probate, and criminal cases. Circuit court judges can order money judgments, fines, jail or prison time, probation, injunctions, and other types of remedies. Circuit courts exist by the law in our state constitution and the rules are found in Chapter 753 of the Wisconsin Statutes.