<prompt> Human: Our son who is now 3 months old, got his SSN after birth.Can we be proactive and add his SSN to be a authorized user on our credit cards, to start building his credit history?  <response>: I see no reason to. He wont need credit until he is at least 18. At that time, you can add him to this same card. All of its history will transfer to him at the point you add him. 