Re-registering children’s birth after marriage in the UK?

[DartmoorWanderer]

I’ve just seen a post on TikTok about this and it says that if you were unmarried when your children were born, you need to re-register them after your marriage.

Why? My parents never did this with me, and I get the feeling it’s a bit too late now! What actually happens if you don’t do this?

I updated my son's birth certificate this way - I mentioned in passing when registering his birth that his dad and I had a wedding booked, and they explained the process of re-registering to us. All went to plan, we returned a few months later with the wedding certificate and an updated birth cert was printed with the family surname.

but so what if there were? Would they have a claim to our estate, that we have passed to each other and then our known named children in our will? Or, more pertinently, would they have any more claim if we dont re-register our named children who are the named beneficiaries of our estate?