Oklahoma Certificate of Service is a document issued by the Oklahoma court system to certify that a court document has been served to the other party in a legal dispute. This document is used to prove that the other party was aware of the legal dispute, and that the court document was properly served. There are two types of Oklahoma Certificate of Service: one for service by mail and one for service in person. The Certificate of Service by mail must include the date of mailing, the name and address of the person or entity to whom the notice was sent, and the name of the person who served the document. The Certificate of Service in person must include the date of service, the name and address of the person or entity served, and the name of the server. Both types of Certificate of Service must be signed by the server and filed with the court.