Legal Question in Family Law in California

You do not officially, legally have to do anything, unless there is a paternity and custody order in place. If he is in her life, however, and you moving out of state would interfere with that, he would have the right to haul you back to California for up to six months to face a judge and get a custody order that provides for him to have visitation. If circumstances warrant, he could even ask that she be returned to California to live with him. It also does not look good at all being the parent who unilaterally cuts the child off from contact with the other parent. That would give him a big advantage if it does wind up in court. It's far better, both from a legal standpoint and for your daughter, to collaborate with her father about your move and make arrangements for him to be in her life.