Generally speaking, if you go to court seeking child support, you must first establish paternity and the child's name will be changed to match the fathers'.  If you have a very good reason for not changing the name, the Court will consider it, there is no rule of law requiring the name change, per se.  However, if Dad ask for the name change he will get it; at least I have never seen this request denied.

You should also note that name and support are not related.  The child's name is a matter related to paternity, not support.  In other words, the father's obligation to pay support is not dependent on the child having his last name, it is a matter of public policy that children receive support from both parents.  

The operative question you have not asked, and I venture to guess you may have a problem, is visitation.  A father's obligation to support a child and right to access and visitation with that child are also two distinct issues and in Texas, they are not interdependent.  

Now, if you have already established paternity and the father is paying support and you are seeking to change her name to match yours, you have to serve the father with a copy of the petition to change name and he is a necessary party.

Roy L. Reeves

www.planoattorney.net