WAC 110-03-0090. Proof of service

A party may prove that an opposing party was served with documents by providing any of the following: (1) A sworn statement by the person who served the document; (2) The certified mail receipt signed by the recipient; (3) An affidavit or certificate of mailing; (4) A signed receipt from the person who accepted the commercial delivery service or legal messenger service package; (5) Proof of fax transmission; or (6) Acknowledgment by the party being served.