(a) Unless otherwise provided by Rental Housing Commission regulations, any information or document required to be served upon any person shall be served upon that person, or the representative designated by that person or by the law to receive service of the documents. When a party has appeared through a representative of record, service shall be made upon that representative. Service upon a person may be completed by any of the following ways:
(1) By handing the document to the person, by leaving it at the person’s place of business with some responsible person in charge, or by leaving it at the person’s usual place of residence with a person of suitable age and discretion;
(2) By telegram, when the content of the information or document is given to a telegraph company properly addressed and prepaid;
(3) By mail or deposit with the United States Postal Service properly stamped and addressed; or
(4) By any other means that is in conformity with an order of the Rental Housing Commission or the Rent Administrator in any proceeding.
(b) No rent increases, whether under this chapter, the Rental Accommodations Act of 1975, the Rental Housing Act of 1977, the Rental Housing Act of 1980, or any administrative decisions issued under these acts, shall be effective until the first day on which rent is normally paid occurring more than 30 days after notice of the increase is given to the tenant.