How to get your real last name on birth certificate?

Question

when i was born my mother wasn't married to my father well she was married to my sisters father well my mom gave me and my brother my sisters fathers name not her maiden name not sure why well now my brother is going to have a baby girl and he doesn't want to give the baby the wrong last name help please

Answer 1

This really isn't a genealogy question.

Is he married to the girl who is having the baby?  Does she have any say?

Maybe this would be a good question over in parenting.

Could be a good chance someone else has run into this situation.

Answer 2

you dont have to give it the father's last name, you cant write whatever you want