If you prepare your own petition, file it with the Clerk of Family Court on the 11th floor of the courthouse at. Each of the documents listed below inculde a blank form and the instructions to fill out that form.Click "Child Custody in Philadelphia County" for complete information, forms and instructions. Civil Contempt form. Box 1: Print in the county in which you are filing your petition. This purpose of this packet is to provide you with the information and documents you may need to start or respond to child custody actions. To open a child custody case, you must file your Complaint or Petition with the Clerk of the Court hearing your case. You must also pay a filing fee. Philadelphia County (Custody): Petition to Modify Custody. Do you need to file an emergency custody petition?