<prompt> Human: I am 23 and should have no credit history to my knowledge. I have an Amex that is linked to my parents account for emergencies and a debit card for my small bank account but thats it. Credit sesame shows there are 2 AMEX cards in my report that each have 11K racked up in debt. On July 27 it said Transunion reported a decrease in my score down to 4. Yes, 4, as in the number after 3. Then on August 12 it says a new authorized user was added by a creditor, which I assume is AMEX. Then also on the 12th is says there was a score increase and Im now at 640, when I used to be at 730 originally. Has my identity been stolen? I was traveling on August 12 and my have used my parents Amex that has my name on it because there are no fees abroad, but I cant remember. Who do I call? What do I do? Should I be freaking out or is this possibly just a mistake thats easy to fix?  <response>: You say this:August 12 it says a new authorized user was added by a creditorAnd this:traveling on August 12 and my have used my parents Amex that has my name on it So to me, the explanation here seems pretty clear to me. If you were using your parents Amex that has your name on it, that obviously means you were an authorized user. Hence, that card will show up on your credit report because Amex reports authorized users to credit bureaus. If your parents had or have an 11K balance on their main Amex that you are a user on, itll get reported on your credit report as well.I mean, Credit Karma will literally tell you what your responsibility for the card is. Go to the accounts tab and click the new cards. It will say Responsibility: XXX, like thisIf you are just an authorized user, its as simple disputing the card off your report or calling the credit bureau and tell them to remove you. Authorized users arent financially responsible for the bill. 