Washington Revised Code Title 50. Unemployment Compensation § 50.32.170. Decision final by agreement

No appeal from the decision of an appeal tribunal, or of the commissioner, or of any court in any proceedings provided by this title may be taken subsequent to the filing with the appeal tribunal, commissioner, or court which rendered the decision, within the time allowed for appeal, of an agreement in writing approved by all interested parties to the proceedings, providing that no appeal will be taken from such decision. The provisions of this section shall be jurisdictional.