Cal. HSC § 102535

An application may be filed with the State Registrar for the delayed registration of birth of any person born in this state whose birth is not registered. The application may be made only by the person whose birth is being registered if he or she is 18 years of age or over at the time of filing the application. If the person whose birth is being registered is under 18 years of age at the time of filing the application, the application may be made only by his or her mother, father, legal guardian, or the attending physician or principal attendant at birth.