My question involves adoption law for the State of: Illinois
I have legal custody of my daughter 4 month old daughter and am the only person on her birth certificate she also has my maiden name. Her biological father has never met her even though I have tried time and time again to introduce them. I am taking him for child support but the process is not completed. I plan to remarry and have more children. At that time, I would like to change her last name to that of my future husband's and that of her other brothers and sisters. If at that time bio dad is paying child support but still uninvolved in her life otherwise will I need his permission to change her last name? I have no problem asking him for permission but I would like to know both parties rights should he not agree.
My fiancé and I do not want to go through with an adoption should her bio dad want to one day be involved. When she is old enough to understand we plan on telling her about her bio dad though no one can never know if he will choose to meet her. And that is a risk I'm not willing to take in regards to her feeling left out our embarrassed that she has a different lasts name than the rest of the family.

