The Los Angeles Times on Sunday has column by Liz Weston. Yesterday there was one called How Children can build good credit. scores.. The link is below
Something to think about.
Very strange that you posted this because out of the blue yesterday I was wondering when I could do this for my son. He is still a baby but I wondered at what age you could add them as an authorized user to get them a credit history.
I would wait until your child is near or at adulthood. The history of account transfers completely not just when you made the person authorized user on the account. Secondly one the points of the article the child needs to build their own credit history. The parnets in the article had made their son an authorized user on their accounts. The son was declined for an auto loan because the credit history was not his own. In other words the son was not the one responsible for building the credit history on authorized user account.