Issuance. In the course of a formal investigative proceeding the officer conducting the investigation may issue a subpoena directing the party named therein to appear before the officer conducting the investigation at a specified time and place to testify or to produce documentary evidence, or both, relating to any matter under investigation.

Service. Service of subpoenas shall be effected in the following manner:

Service upon a natural party. Delivery of a copy of a subpoena to a natural person may be effected by—

Handing it to the person;

Leaving it at his or her office with the person in charge thereof or, if there is no one in charge, by leaving it at a conspicuous place there;

Leaving it at his or her dwelling place or usual place of abode with some person of suitable age and discretion who is found there; or

Mailing it by registered or certified mail to him or her at his or her last known address. In the event that personal service as described in this paragraph is impracticable, any other method whereby actual notice is given to the respondent may be employed.

Service upon other persons. When the person to be served is not a natural person, delivery of a copy of the subpoena may be effected by—

Handing it to a registered agent for service, or to any officer, director, or agent in charge of any office of such person;

Mailing it by registered or certified mail to any such representative at his or her last known address; or

Any other method whereby actual notice is given to any such representative.

Witness fees and mileage. Witnesses appearing pursuant to subpoena shall be paid the same fees and mileage that are paid to witnesses in the United States district courts. Any such fees and mileage payments need be paid only upon submission of a properly completed application for reimbursement and in no event need they be paid sooner than 30 days after the appearance of the witness pursuant to subpoena.

Enforcement. Whenever it appears to the General Counsel that any person upon whom a subpoena was properly served pursuant to these Rules is refusing to fully comply with the terms of that subpoena, then the General Counsel, in his or her discretion, may apply to the courts of the United States for enforcement of such subpoena.