Legal Question in Family Law in California

"On the birth certificate" is a layperson's concept that has nearly zero legal relevance. What gives a man parental rights (and obligations) is one of three things, only. 1. He is married to and cohabitating with the mother at the time of conception. 2. He and the mother sign and properly file a declaration of paternity in which they both agree he is the legal father. 2. He or the mother files a court proceeding to have him declared the legal father and the court enters a judgment that he is the father. If any one of those things happened or is true, you must have his consent or a court order. If none of those happened/is true, you do not need anything from him.