After you file

@SForrestLO 
Hi there! I’m in a situation that hopefully you can give me advice on what to do.

My daughters father and I both e-filed around the same time, I didn’t realize I was getting EITC from my daughter because I selected the option stating that I had an agreement with the other parent and he would be claiming her. I got accepted and his return got rejected. I still want him to be the one to receive child tax credit and EITC for our daughter, I know I will need to amend mine by mail. Will he have to wait to paper file his return until after I send in my amended return? Also, will I most likely have to pay back what I will receive for the first return?