Changing a Child’s Birth Certificate Return to Establish Legal Paternity page CA Health and Safety Code Section 102425 (a)(C) states: “If the parents are not married to each other, the father’s name shall not be listed on the birth certificate unless the father and the mother sign a voluntary Declaration of Paternity at the hospital before the birth certificate is submitted for registration. The birth certificate may be amended to add the father’s name at a later date only if paternity for the child has been established by a judgment of a court of competent jurisdiction or by the filing of a voluntary Declaration of Paternity.” Therefore a birth certificate alone DOES NOT establish legal paternity when parents are unmarried. Only signing a Voluntary Declaration of Paternity or obtaining a judgment in court legally establishes paternity for the children of unmarried parents. Parents may complete this Declaration at any time after the child’s birth, and both parents must voluntarily sign in front of an authorized witness. For more information about birth certificates, please contact the California Department of Public Health Office of Vital Records at 916-445-2684 or email VRmail@cdph.ca.gov.