If you have not yet filed your return, to update you bank account information, sign back into your account and click on the "File" tab. Continue until you get to the screen asking how you would like your refund, once on this screen select "direct deposit", and continue with the below steps:

1. Ensure the box underneath the account info stating I want my refund deposited into this account is unchecked.
2. Scroll down and click Continue.
3. A page will display that says, Let's get your bank account info.
4. Enter your new or updated account info you want your 2016 refund deposited in to.

If you have already filed your return, there is a slight possibility that you might be able to update your bank account number.

 If you had chosen the Refund Processing Service (allowing TurboTax to take their fees out of your federal refund), you can try going to the Santa Barbara Tax Products Group website for assistance. When you use the Refund Processing Service, your refund is sent to a "middle man" (Santa Barbara Tax Product Group) who then transfers your fund to your bank account and transfer TurboTax's Fees to their account. So if you can speak with someone there, they may be able to update your direct deposit information before they attempt to deposit the funds. 

If you did not use the Refund Processing Service, you may be able to contact the IRS directly (800-829-1040), after the return has been accepted, and see if they might be able to update your bank account information.

If you aren't successful in getting the bank account information updated, don't worry. If the IRS/Santa Barbara Tax Product Group is unable to deposit your refund amount they will send you a check in the mail.