I added my sister as an additional cardholder to help her build credit. It said in the terms and conditions that they have to right to verfiy, share, and exchange information with consumer agencies for both account holders and additional cardholders. Therefore, doesn't that mean that her credit history will be affected. I called customer service; he said that it doesn't help her build credit. Another person said, "It builds credit with AMEX; then she can apply for her own AMEX card to build credit with the credit bureau." A member of yahoo! answers said that he was added as an additional cardholder and the record was recorded in his credit report. So, which one is it? Will she build credit or not?