How can the father of a child be ordered to pay child support if his name is not on the birth certificate and his last name is unknown?

If the couple are unmarried paternity must be established before a child support petition can be filed. If the father refuses to take a paternity test the court can order him to do so. The matter of not knowing his last name is indeed troubling and may be reason enough for the court to deny any motion for testing or support. Contact the department of family and children's services or the state health and human services in the state of residency for assistance.