Dealing with paternity, birth certificates, and odd naming systems day in and day out, here’s my experience in Minnesota-
If the parties are not married a birth certificate means little of nothing. A paternity order or a Recognition of Parentage is what legally names a father. So if a father doesn’t sign a birth certificate it’s not a big deal. Also, birth certificates can always be modified whether it be to change the child’s name or add a fathers name.
A Recognition of Parentage is done in the hospital also, usually at least a day after the baby is born (and mom is more lucid?). If the parties have only done a BC in the hospital, a ROP can be done at a later date. I’ve seen cases where the child is 4 and the parents have just signed the ROP. Both parties must sign the ROP.
If the parties are married a birth certificate is more important, as paternity is assumed. If a married mother does not list her husband’s name on the BC, he is still presumed the father. She could write the father being Ben Affleck, doesn’t matter.
There’s the legalities of that stuff. A bit off topic, I know.
When LilMiss was named, her dad was not in the room. We had somewhat agreed on a name, but I got to say what I wanted on her BC. If Emo disagreed, we could’ve changed her name on the ROP (no, we weren’t married) and followed through with changing the BC later. Or, when we went to court to legally set paternity we could’ve asked the court to change her name, again following it up with amending the BC. I see this often with surnames. Once John Doe has been proven to be the father, Minnie Anderson becomes Minnie Doe if the parents so choose.
If Emo and I were married we wouldve just had to amend the BC to reflect a name change for LilMiss. I do not know if there is a time frame for this, but of a child’s name is particularly horrendous s/he can always change it as an adult.
Technically, my last name is not correct. My dad’s BC name and SSN name are slightly different what he has always used. He has always worked, got married, used financial institutions with the “wrong” last name and no one has ever bothered him about it. (My grandfather, feeling a twinge of nostalgia, gave my dad and his younger brother the original German surname, not the Americanized surname the rest of the siblings had).
Also (and this is it, I swear), when people get married they can change surnames if they so choose. I’ve known a few people who left the church with surnames that have no relation to the names they entered with. You can also change your surname to whatever you want when divorcing.