Legal Question in Banking Law in Illinois

Re: Bank mistake

The safest thing to do would be to tell the bank.

If you are looking for advise on how to keep the money, I would not want speculate without talking to you about more details. There are cases that, when the bank makes such a mistake and the "innocent" account holder spends the money, that someone in your position would be free from liability. But there are several missing pieces to discuss before you can be sure that you won't need to return the cash.