California Proof Of Service For Personal Service Or By Notice And Acknowledgement Of Receipt is a legal document that certifies the delivery of court documents. It is used to prove that the person or parties to whom the documents were sent received the papers. There are two types of California Proof Of Service: Personal Service and By Notice and Acknowledgement of Receipt. Personal Service involves a third party, often a process server, delivering the documents directly to the defendant or other party. This type of service requires a proof of service form to be completed and signed by the process server. By Notice and Acknowledgement of Receipt involves mailing the documents to the defendant or other party by registered mail or Certified Mail Return Receipt Requested (CM RRR), and then obtaining a signed receipt from the person or party indicating that they have received the documents. This type of proof of service requires the completion of a proof of service form and the submission of the signed receipt to the court.