<prompt> Human: When I was growing up my dad had me on his credit card and I am still on it since its my longest line of credit, I just dont use it and when I went to go buy my first home 2 years after college my credit score was 800. I was able to buy a house before I had a car loan because he had helped me establish credit for years. I didnt even know I was on his cards until I was mostly through college. I have a son who is 1 years old right now and I want to make sure I set him up the best that I can. I would not be giving him a card now or in the future because my limits would be way to high to give to a kid, its more about just having him as a user to build credit.I have already started some savings accounts to hopefully be able to help him when he gets older as well. But, I would like to make sure he has the best credit history possible when he gets older like my dad did for me.The advice I am looking for is if anyone can tell me if this would help him in the long run or not.  <response>: AFAIK it doesnt matter whether you add your son now or at age 16. The account will report on his credit report exactly the same as it reports on yours. e.g. If you opened your card in 2010, it will show up on his report as being opened in 2010 whether you add him as an authorized user today or 15 years from now. 