Have you already e-filed your return? If so, then you
will not be able to change your bank details. You will have to wait to see if
your tax return is accepted or rejected
by the IRS.
If the return is rejected, then you can update your information
and resubmit your return. Should the tax return be accepted and the IRS (and State, if any) cannot
deposit your refund to your account, then a paper check will be mailed to you.
You can refer to
this TurboTax FAQ for complete information:
https://ttlc.intuit.com/replies/3302459
