Washington Confirmation of Joiner of Parties Claims And Defenses is a legal document used in Washington State to bring additional parties into a civil lawsuit. It is a formal document that confirms that the parties to the lawsuit are agreeing to a joiner, or the addition of new parties to the suit. The document outlines the claims and defenses of each of the newly-joined parties and allows them to be held liable for the outcome of the case. This document is usually submitted to the court in order to make the joiner official. There are two types of Washington Confirmation of Joiner of Parties Claims And Defenses: voluntary joiner and involuntary joiner. Voluntary joiner is when the parties to the lawsuit agree to add additional parties. Involuntary joiner is when the court orders the addition of a new party to the suit. In either case, the Washington Confirmation of Joiner of Parties Claims And Defenses must be submitted in order to make the joiner official.