Rule 21. Service of Papers

(a) When Required: Except as otherwise required by these Rules or directed by the Court, all pleadings, motions, orders, decisions, notices, demands, briefs, appearances, or other similar documents or papers relating to a case, including a disciplinary matter under Rule 202, also referred to as the papers in a case, shall be served on each of the parties or other persons involved in the matter to which the paper relates other than the party who filed the paper.
(b) Manner of Service:
(1) General: All petitions shall be served by the Clerk. All other papers required to be served on a party shall also be served by the Clerk unless otherwise provided in these Rules or directed by the Court, or unless the original paper is filed with a certificate by a party or a party’s counsel that service of that paper has been made on the party to be served or such party’s counsel. For the form of such certificate of service, see Form 10, Appendix I. Such service may be made by mail directed to the party or the party’s counsel at such person’s last known address. Service by mail is complete upon mailing, and the date of such mailing shall be the date of such service. As an alternative to service by mail, service may be made by delivery to a party, or a party’s counsel or authorized representative in the case of a party other than an individual (see Rule 24 (b)). Service shall be made on the Commissioner by service on, or directed to, the Commissioner’s counsel at the office address shown in the Commissioner’s answer filed in the case or, if no answer has been filed, on the Chief Counsel, Internal Revenue Service, Washington, D.C. 20224. Service on a person other than a party shall be made in the same manner as service on a party, except as otherwise provided in these Rules or directed by the Court. In cases consolidated pursuant to Rule 141, a party making direct service of a paper shall serve each of the other parties or counsel for each of the other parties, and the original and copies thereof required to be filed with the Court shall each have a certificate of service attached.
(2) Counsel of Record: Whenever under these Rules service is required or permitted to be made upon a party represented by counsel who has entered an appearance, service shall be made upon such counsel unless service upon the party is directed by the Court. Where more than one counsel appear for a party, service will be made only on that counsel whose appearance was first entered of record, unless that counsel notifies the Court, by a designation of counsel to receive service filed with the Court, that other counsel of record is to receive service, in which event service will be made only on the person so designated.
(3) Writs and Process: Service and execution of writs, process, or similar directives of the Court may be made by a United States marshal, by a deputy marshal, or by a person specially appointed by the Court for that purpose, except that a subpoena may be served as provided in Rule 147 (c). The person making service shall make proof thereof to the Court promptly and in any event within the time in which the person served must respond. Failure to make proof of service does not affect the validity of the service.
(4) Change of Address: The Court shall be promptly notified, by a notice of change of address filed with the Court, of the change of mailing address of any party, any party’s counsel, or any party’s duly authorized representative in the case of a party other than an individual (see Rule 24 (a)(2), (a)(3), (b), and (d)). A separate notice of change of address shall be filed for each docket number.