Missouri Proof of Service is a document filed with the court to prove that a party to a legal action has been notified of the legal proceedings. It is used in civil court cases to ensure that all parties are aware of the lawsuit and their rights. There are three main types of Missouri Proof of Service: personal service, substituted service, and service by mail. Personal service involves a court representative, such as a sheriff or process server, delivering a summons and complaint to the party, who must sign the document to acknowledge receipt. Substituted service involves leaving the document with an adult at the party's residence or place of business and mailing a copy to the party. Service by mail involves sending the document through the U.S. Postal Service to the party's last known address. Once the Proof of Service is filed, the court will review it and decide if it is proper.