Mandatory service. Every document filed with the Secretary shall be served upon all parties to any proceedings, i.e., Complaint Counsel, respondent(s), and party intervenors, as well as the Presiding Officer. Every document filed with the Secretary shall also be served upon each participant, if the Presiding Officer or the Commission so directs.

Service of complaint, ruling, petition for interlocutory appeal, order, decision, or subpoena. A complaint, ruling, petition for interlocutory appeal, order, decision, or subpoena shall be served in one of the following ways:

By registered or certified mail. A copy of the document shall be addressed to the person, partnership, corporation or unincorporated association to be served at his/her/its residence or principal office or place of business and sent by registered or certified mail; or

By delivery to an individual. A copy of the document may be delivered to the person to be served; or to a member of the partnership to be served; or to the president, secretary, or other executive officer, or a director of the corporation or unincorporated association to be served; or to an agent authorized by appointment or by law to receive service; or

By delivery to an address. If the document cannot be served in person or by mail as provided in paragraph (b)(1) or (b)(2) of this section, a copy of the document may be left at the principal office or place of business of the person, partnership, corporation, unincorporated association, or authorized agent with an officer or a managing or general agent; or it may be left with a person of suitable age and discretion residing therein, at the residence of the person or of a member of the partnership or of an executive officer, director, or agent of the corporation or unincorporated association to be served; or

By publication in the Federal Register. A respondent that cannot be served by any of the methods already described in this section may be served by publication in the Federal Register and such other notice as may be directed by the Presiding Officer or the Commission, where a complaint has issued in a class action pursuant to § 1025.18.

Service of other documents. Except as otherwise provided in paragraph (b) of this section, when service of a document starts the running of a prescribed period of time for the submission of a responsive document or the occurrence of an event, the document may be served as provided in paragraph (b) of this section or by ordinary first-class mail, properly addressed, postage prepaid.

Service on a representative. When a party has appeared by an attorney or other representative, service upon that attorney or other representative shall constitute service upon the party.

Certificate of service. The original of every document filed with the Commission and required to be served upon all parties to any proceedings, as well as participants if so directed by the Presiding Officer, shall be accompanied by a certificate of service signed by the party making service, stating that such service has been made upon each party and participant to the proceedings. Certificates of service may be in substantially the following form:

I hereby certify that I have served the attached document upon all parties and participants of record in these proceedings by mailing, postage prepaid, (or by delivering in person) a copy to each on

Date of service. The date of service of a document shall be the date on which the document is deposited with the United States Postal Service, postage prepaid, or is delivered in person.