My son and his ex have a daughter his ex has announced that she is getting married and is considering changing her daughters surname my son asked me can his ex do this with out his consent ?
//A mother, or father, cannot change a child's surname by herself or himself unless she or he is the only person with parental responsibility. Even then if the other parent objects a Court Order should be made. Any child who has sufficient legal understanding may apply in their own right for the Court's permission to change their name.//
Enrol your child’s new name
You’ll need either:
the agreement of everyone with parental responsibility
a court order
You must try to reach agreement before you seek a court order.