This form is filed with the Court after the service is done. This form is called an Affidavit of Service.11. Enter the name of the person you served. 12. Enter the address where you served the person. An affidavit of service, also sometimes called a proof of service affidavit, is a type of affidavit that relates to legal documents that are filed with a court. All your efforts to effect service should be carefully documented. This will be committed to an affidavit when you complete the RETURN portion of the subpoena. O The Affidavit of Service of Summons and. Start your Service of Process at the Clerk of the Circuit Court. The clerk has one office at every courthouse and multiple at the Richard J. Daley Center.