Without more details we can't answer. We need to know your general locale as laws vary by area. We need to know what your relationship is, and what his relationship is to the child. That's for starters.

Please use the Answer options to provide follow-up info.

I live in Florida. I was 16 when my son was born and started dating my husband when I was three months pregnant. When I contacted my son's biological father he told me in a not so nice way that he wanted nothing to do with myself or my son. Being young and scared I let my husband, who was then my boyfriend, sign my son's birth certificate. We had a daughter a year and a half later and were married two years after that. We split for two years, I had another child with my boyfriend at the time. I moved back in with my husband when that relationship ended. My husband caused me to lose my job, and then kicked me out with no where to go. Thinking of my children I left them in his care until my situation was stable. He has had my children for 14 months and I am ready to get them back. He refuses to let me see them and now I have filed for divorce and custody. I am now going to file a motion for paternity on my son. I don't think it is right that he is keeping my children from me. He is not my son's father. What can I do? What are the chances he will be awarded custody even though he is not my son's biological father but is on his birth certificate and we were not married at the time of his birth?

So the onetime husband "signed the birth certificate", despite knowing he was not the bio-dad. Then he married you and had other children by you. Under these circumstances, I expect the courts would be reluctant to disregard the presumption of paternity, whatever the results of a paternity test might say.

He is probably the legal father of all three kids. He acknowledged paternity of the first child, s the father of the second, and since you were still married when the 3rd child was born, he's the presumed father there.

Unless a challenge is made to his legal status, bio paternity means nothing. I would engage an attorney to fight this. The situation is too complex to go into court without one.