Tempting as it is, don´t take the money. My wife worked in the banking industry and there are agreements between states, and partially on the Federal level, to prevent just this sort of thing. IT basically goes something like, if you knew the money wasn´t yours, even if you got it by mistake, it is to be considered a "good faith" mistake and your responsibility is to report it to the bank. If you do take the money, and bank pursues, you can be held personally liable for the money, or any difference that you are unable to return. It´s just not worth it.