If you already e-filed with the wrong banking information, the bank will reject the refund. It will go back to the IRS, and the IRS will mail a paper check to the address on your tax return.
According to the IRS:
- If the return has not already posted to our system, you can ask us to stop the direct deposit. You may call us toll-free at 800-829-1040, M - F, 7 a.m. - 7 p.m.
- Generally, if the financial institution recovers the funds and returns them to the IRS, the IRS will send a paper refund check to your last known address on file with the IRS.
- If you have contacted the financial institution and two weeks have passed with no results, you will need to file Form 3911, Taxpayer Statement Regarding Refund, to initiate a trace. This allows the IRS to contact the bank on your behalf to attempt recovery of your refund. However, if funds are not available or the bank refuses to return the funds, the IRS cannot compel the bank to do so. The case may then become a civil matter between you and the financial institution and/or the owner of the account into which the funds were deposited.
From the IRS: What should I do if I entered an incorrect routing or account number for direct deposit of my refund?
https://www.irs.gov/faqs/irs-procedures/refund-inquiries/refund-inquiries-18
