The Maryland Certificate of Service is a document issued by the Clerk of a Circuit Court in the state of Maryland. It is a document that certifies the service of process of legal documents such as a Summons and Complaint, or a Petition to the court. It is important for filing legal documents because it serves as proof that the document was properly served. There are two types of Maryland Certificate of Service: the Certificate of Service by Mail and the Certificate of Service by Posting. The Certificate of Service by Mail is used when legal documents are sent by mail to the defendant. The Certificate of Service by Posting is used when documents are posted on the defendant's property or in the courthouse. The Certificate of Service must be completed and signed by the person who served the documents. It must also include the date and time of service, the name and address of the defendant, and the name of the court.