I want my younger brother (just entering college) to get a head start on the credit game. I want to add him on as an AU on one of my accounts so he can start getting some credit. Probably will do AMEX so he gets backdated a couple of years. My only question is, does this affect my score in any way? Is there a HP or anythign involved?
This will not affect your score. There are no inquiries on either of your reports to add him as an AU. Of course, his usage will be reported as your usage, but I'm sure you already took that into consideration.