Hi, thank you for your question. Just a bit more information required to fully assist you:
-Please confirm if he and the mother are in England or Wales?
-How old is the child?
-How did he find out he is not the father?
In the circumstances he may wish to apply to court for declaration of parentage (you can find more about the process here: https://www.gov.uk/child-maintenance/disagreements-about-parentage)
At this time, as he is registered on the birth certificate he would be known as the father and there are legal implications, for example child maintenance liability and inheritance issues if this is not legally cleared up to show that he is not the father.
I hope this assists you. If you found this information helpful please provide a positive rating using the stars at the top of this page. I will not be credited for your question without a positive rating. Thank you.
My name is ***** ***** I have been a solicitor for more than 30 years.
I am afraid my colleague failed to understand what you were concerned about.
A Declaration of Parentage is the last thing that your son wants as it would remove his name from the Birth Certificate and confirm that he is NOT the biological father.
As things stand he is the father so far as the law is concerned.
Of course this was base don a falsehood - and technically this means an offence has been committed - but frankly it is one that has often been committed and since it is simple for the mother to say "I thought he was" there is unlikely ever to be a problem.
The only difficulty will arrive if the biological father turns up and makes an applictaion for the Declaration of Parentage referred to above.
From your point of view in your Will you can avoid problems simply be referring to your granddaughter by her full given name rather than just "my granddaughter"
I hope that this is of assistance