Birth certificate after marriage

[missamericanaandtheheartbreakprince]

Hey everyone!
I get married on Saturday and really looking forward to it. I had an email from my celebrant this week and she briefly mentioned we'll have to get our children's birth certificates updated. Now I've looked online to see if there's any guidance- but my eldest son (4 years old) isn't biologically my fiancés. He took him on when he was very very tiny, and has raised him as his own. His 'father' isn't on his birth certificate, and left when I was still pregnant. it's just me on his birth certificate. We have no contact with his father either, and he no longer lives in the country.

I was wondering, when we update our little girl's certificate (and my name on our sons)... because he currently has my maiden name as his last name, will I be able to change it to what my married last name will be?

Thank you for any advice you can give! And sorry if it makes no sense!

I think you are only required to do it where the marriage is of the child's parents, so you don't need to do it for your first child. Are you planning on changing his name?

@CuriousGeorge80 yes I really would like to, just I don't know how to go about doing it x

I think the requirement to re-register children after marriage only applies to children who were born to the parents before they were married if you see what I mean!
So in your case, your son's birth certificate won't be affected as he isn't a child of you and your soon-to-be husband.
But you will need to re-register your daughter once you are married.
I've assumed your fiancé is your daughter's dad.
Hope that helps.

@GherkOut
Amazing thank you so much! I'm wondering wether I'll be able to register a deed poll for his last name. It's the only thing I can find online without having to go to court. I have tried, and there is literally no way I'm able to get ahold of his bio dad.

To change your son's name, you would probably need to do it by deed poll. I think that's a fairly straightforward process.

Could you look at a step parent adoption for your partner? I think since your sons Dad isn’t in the birth certificate he won’t have PR so that would make that side of things a little easier..would mean your partner can make parental decisions for your son and would become his Dad.