An Arizona Summons on Third-Party Complaint is a court document served by a party to an existing lawsuit in Arizona to a third-party defendant who is believed to be responsible for the claims in the lawsuit. It informs the third-party defendant of the lawsuit and their responsibility to respond to the claims. There are two types of Arizona Summons on Third-Party Complaint: the Original Summons and the Service of Process Summons. The Original Summons is served by the plaintiff on the third-party defendant to initiate the lawsuit and inform the defendant of their responsibility to respond to the claims. The Service of Process Summons is served by the court or the plaintiff's attorney on the third-party defendant after the court has accepted the complaint and assigned a case number to the lawsuit. Both types of summons require the defendant to provide a response to the claims within a specific timeframe.