<prompt> Human: Kind of long story, so TL;DR below.I used to have two Chase accounts -- one checking and one savings. I had automatic payments set up to go from checking to savings, but I never really paid close attention to savings other than that. Approximately a year ago, I switched banks and closed both Chase accounts with a zero balance in each. Yesterday I got a letter from Chase stating that I owed them approximately 500 on the closed savings account. I called them, and it turns out that at some point before I closed the account, Chase accidentally deposited the money in my savings account, but I never noticed. They didnt notice it until after I closed the account.My question is, what do I have to do with this? If I dont pay them back, will it negatively affect my credit score or be harmful in some other way? TL;DR Chase accidentally gave me money. Do I have to give it back?  <response>: If theyve informed you of the mistake, and you choose not to take action on fixing it, you are committing theft.Arrange a repayment plan with them immediately, demand no interest be charged as the error is theirs, not yours, and honor the repayment schedule. A 500 debt can tank your credit just as badly as a 50000 debt, if left unpaid.HTH 