Being an authorized user does not make you responsible for the card if you are not married to the card holder. Think about it this way. When I was 15 I was an authorized signer on my father’s credit card and no where on my credit report does it state this account. Also, this authorized user is not contractually responsible for the debt.
Also, it’s a little different when married couples are involved. If I am not a cosigner but an authorized user on a credit card, I am equally responsible for the debt because we are married.
Or think about this…a business that sometimes have their employees as authorized users. If the business doesn’t pay the debt the credit card company doesn’t have the right to pursue the authorized user. They have to go after the company.