17 CFR § 201.150 - Service of papers by parties.
(a) When required. In every proceeding as defined in § 201.101(a), each paper, including each notice of appearance, written motion, brief, or other written communication, shall be served upon each party in the proceeding in accordance with the provisions of this section; provided, however, that absent an order to the contrary, no service shall be required for motions which may be heard ex parte.
(b) Upon a person represented by counsel. Whenever service is required to be made upon a person represented by counsel who has filed a notice of appearance pursuant to § 201.102, service shall be made pursuant to paragraph (c) of this section upon counsel, unless service upon the person represented is ordered by the Commission or the hearing officer.
(c) How made. Service shall be made electronically in the form and manner to be specified by the Office of the Secretary in the materials posted on the Commission's website. Persons serving each other shall have provided the Commission and the parties with notice of an email address.
(1) Certification of inability to serve electronically. If a person reasonably cannot serve electronically (due, for example, to a failure to have a functional email address or a lack of access to electronic transmission devices due to incarceration or otherwise), the person promptly shall file a certification under this paragraph that explains why the person reasonably cannot comply using any additional method of service listed in § 201.150(d). The filing also must indicate the expected duration of the person's reasonable inability to comply, such as whether the certification is intended to apply to a solitary instance of service or all instances of service made during the proceeding. The certification is immediately effective. Upon filing the certification, it will be part of the record of the proceeding, and the person may serve paper documents by any additional method listed in § 201.150(d).
(d) Additional methods of service. If a person reasonably cannot serve electronically, or if service is of an investigative subpoena pursuant to 17 CFR 203.8, service may be made by delivering a copy of the filing. Delivery means:
(1) Personal service—handing a copy to the person required to be served; or leaving a copy at the person's office with a clerk or other person in charge thereof, or, if there is no one in charge, leaving it in a conspicuous place therein; or, if the office is closed or the person to be served has no office, leaving it at the person's dwelling house or usual place of abode with some person of suitable age and discretion then residing therein;
(2) Mailing the papers through the U.S. Postal Service by first class, registered, or certified mail or express mail delivery addressed to the person;
(3) Sending the papers through a commercial courier service or express delivery service; or
(4) Transmitting the papers by facsimile transmission to the person required to be served. The persons so serving each other shall have provided the Commission and the parties with notice of a facsimile machine telephone number.
(e) When service is complete. Electronic service is complete upon transmission, but is not effective if the sender learns that the transmission failed. Personal service, service by U.S. Postal Service express mail or service by a commercial courier or express delivery service is complete upon delivery. Service by mail is complete upon mailing. Service by facsimile is complete upon confirmation of transmission.