<prompt> Human: I want to give my kids every advantage thats realistically possible. To help them get a credit history, I was planning on adding them as authorized users on one of my cards, but not give them a card - when is a good time for this? As a teenager? At 18? 21?  <response>: You can add them whenever. They will receive the entire history of the card, even if it was opened before they were born. If you wish to do this, just do it a couple months before they turn 18. Make sure you have a discussion with them about responsible credit card use. If you do this, and your card is in good standing, you will give them the ability to get their own cards at a much higher credit limit then a normal 18 year old would have. It would be unfortunate if your attempt to help your children lead to them becoming massively in debt due to having access to something they wouldnt have normally had. 