Minnesota (AO 399) Waiver of the Service of Summons is a legal document that is used to waive service of summons when a summons is served on a defendant. The waiver allows the defendant to agree to a lawsuit without having to be formally served with a summons in person. There are two types of Minnesota (AO 399) Waiver of the Service of Summons: Waiver of Service of Summons and Waiver of Service of Summons by Mail. Waiver of Service of Summons requires the defendant to sign the form in front of a notary public or other person authorized to take oaths. Waiver of Service of Summons by Mail requires the defendant to sign the form and return it to the court. Once the paperwork has been properly executed, the court will enter an order deeming the summons properly served and the lawsuit can proceed.