It’s a common misunderstanding or misconception that just because people change the name of their child that somehow that establishes a parent-child relationship or some kind of an informal adoption between the step parent and the child but that’s not the case.
Simply changing the child’s name there’s nothing to establish a parent-child relationship between the step parent and that child or some kind of an adoption. There is no such thing and under Texas law as “informal adoption” even if the child’s name is changed to reflect that of the family and maybe the other sibling group, the other blended sibling group, because when you remarry maybe they have new kids and the new kids have the name of the family and maybe the other children brought in have the name of the family but the one left out feels awkward and so that’s oftentimes a very good reason to change the last name of the child.
The father in that case, the biological father, has a right to be noticed in the event that you’re trying or attempting to change the name of the child. Of course, he has a right to step in and ask the court to not change the child’s name or object to it. The court will make that determination essentially on what’s known as a best interest standard and determine what’s in the best interest of the child whether or not he should continue to have the biological father’s name or that of his new or his or her new family.
Oftentimes what I’ve seen in that circumstances is that the courts will compromise and hyphenate the child’s name so that the father’s name appears as well as the surname of the new family in that way the child can feel completely assimilated and a part of his or her new family.