(1) Service defined. Service means sending or delivering, in accordance with RCW 34.05.010(19) and this rule, the following documents in an adjudicative proceeding:

(a) Documents submitted to the commission for filing that must be sent or delivered to the parties in that proceeding;

(b) Documents that are not submitted to the commission for filing but that are formally exchanged between parties (e.g., data requests and responses); or

(c) Orders, notices, or other documents the commission enters or issues that must be sent or delivered to the parties or to any other persons to whom service may be required.

(2) Designation of person to receive service. Each party in an adjudicative proceeding must designate at least one person to receive service of documents relating to the adjudication. A party may designate more than one person to receive electronic service subject to any limits the presiding officer may establish on the number of persons each party may designate. Service on the person or persons who a party has designated as its representative(s) is valid service upon the party, except as provided by law.

(3) Contact information. In its initial filing in the adjudicative proceeding, each party or person seeking to become a party must designate the individuals to receive service on behalf of the party or person and must supply the following information about each such individual:

(a) Name;

(b) Mailing address;

(c) Telephone number;

(d) Email address; and

(e) Relationship to party (e.g., counsel, executive director, etc.).

(4) Master service list. The commission will maintain a master service list for each adjudicative proceeding. The commission will include an initial master service list as an appendix to the prehearing conference order, if any, in the proceeding and will maintain a current master service list on the commission's website as a separate document under the docket number for the proceeding. Parties must provide written notice to the commission and the other parties of any changes to the master service list.

(5) Contents of master service list. The master service list will contain the contact information for each party to the proceeding and each party's designated representative(s) for service. If the commission requires both paper and electronic service, the master service list will identify the one person representing each party who must be served paper copies in addition to electronic service.

(6) Electronic service required.

(a) Each party must serve documents by delivering electronic copies to each person on the master service list. Unless otherwise required by law, a party need not deliver a paper copy of the documents to any other party to perfect service but may serve a paper copy of any documents in addition to the electronic copies on a party that requests a paper copy.

(b) The commission will only serve documents electronically on each party's designated representatives, except as required otherwise by law. To the extent a statute requires a party's agreement to electronic service, the commission presumes that by participating as a party to an adjudicative proceeding, each party agrees to electronic service of all documents in that proceeding, including orders and notices the commission serves, unless the party states on the record at or before the initial prehearing conference or the hearing, whichever occurs first, that the party does not agree to electronic service. If a party lawfully insists on paper service, the commission will serve all documents electronically and also will serve on that party the paper documents the applicable statute requires be served in paper form.

(7) When service is deemed complete. Unless otherwise ordered by the commission in a particular proceeding, service is complete when the document being served has been verifiably sent to the recipient's designated email address. Parties serving documents should maintain records of documents sent by email and, to the extent practicable, should confirm successful delivery.

(8) Certificate of service. Each submission of one or more documents for filing to meet a single deadline in an adjudicative proceeding must include a certificate of service that states substantially as follows: