Contact bank where the refund is erroneously going and let them know of your mistake.  They will be getting the refund unless the account you entered is not a open account..  If there is no account at that bank matching what you entered then the client will get a paper check a week later.  Otherwise it will be deposited to wrong account.

And what is IRS / Banker position on this?  Not our problem

Wow, that took much longer than I expected!

AND, it picked up *both* of the ones nominated in one question :joy:

Well, in fairness to the system, the inability to file Illinois and Alabama did shrink the pool of number of returns that could have generated the question.

Your client will get the refund check or the bill.