You can sign create a free account with all three ratings agencies (Equifax, Experian, TransUnion) and see your report and dispute it on each one. If it it shows up as an authorized user account you can dispute it with each one saying your have no financial obligation for that account and they should remove it. That would be my first step of something similar happend to me.

If I remember correctly they remove it from your report while they verify it. if the bank insists on keeping it there then you have to take it up with them but usually most banks have no problem removing authorized users from the report.

You can get all reports for free and it's a good idea to have an account with each so you can freeze your credit. They all try to get you to subscribe to credit monitoring but you can do everything you need without paying.

Credit scores are such a ****ty creation. I have a client buying a house and has decided to get a mortgage for it at least until their current house sells. The house is $1.3m, the house being sold is worth $900k and paid off. They have several million in liquid assets yet somehow a Target card wasn't on autopay and they missed a couple of bills and thus payments over a balance of about $100. His current score is 620 when it's usually 820 and at exactly the wrong time.

He's already paid off target. I told him to create a profile at each agency and dispute the claim that it's unpaid and since it's paid off I doubt Target will fight it. Such a silly thing though.