A notice, order, decision, or pleading required by this chapter to be served upon a party shall be served upon the party or upon the representative designated by the party or by law to receive service of papers. If a party has appeared through counsel, service may be made upon the counsel of record.
Service on a respondent shall be directed to the last known address of the respondent on file with the Director and shall be completed by one of the following methods:
Proof of service, stating the name and address of the person on whom service is made and the manner and date of service, may be shown by one of the following methods:
If service is by personal delivery, it shall be deemed to have been served at the time when delivery is made to the party or other person served in accordance with § 4105.2(b).
If service is by certified mail, it shall be deemed to have been made on the date shown on the return receipt showing delivery of the notice to the party or refusal of the party to accept delivery.
If the party is no longer at the last known address as shown by the records of the Director, and no forwarding address is available, service shall be deemed to have been made on the date the return receipt bearing that notification is received by the Director.
D.C. Mun. Regs. tit. 17, r. 17-4105