Unfortunately, once you have filed your return you can no longer make changes to the direct deposit information. If your financial institution rejects the deposit, the government will mail your refund check. If your return gets rejected, you can update your account information and any issues that caused the rejection.
Please see the FAQ: What if I entered the wrong bank account for direct deposit? for additional information.
I'm having this same issue, but I have not yet filed. It simply states that it will 'deposit the refund in Credit Karma account ****1234'. But that is not the right account (I had to change it last year due to fraudulent activity). There is no option that I can find within TurboTax to change that account number. Am I missing it?
if you chose to have your TurboTax fees deducted from your federal refund then the banking information on the tax form is the information to send your refund to the third party bank. That bank gets your refund first from the IRS. They take out your TurboTax fees and send the rest to you---and that bank has YOUR direct deposit information.
When you choose "refund processing" TurboTax gets its fees when the IRS releases your refund. Your refund goes to the third party bank. The bank takes out your fees and then that bank sends the rest of the refund to you.
How can I see my TurboTax fees?
https://ttlc.intuit.com/questions/2565973-how-do-i-review-my-fees-in-turbotax-online
What is Refund Processing Service?
Santa Barbara Tax Products Group, LLC (SBTPG) is the bank that handles the Refund Processing Service when you choose to have your TurboTax fees deducted from your refund. This option also has an additional charge from the bank that processes the transaction.
You can contact them SBTPG, toll-free, at 1-877-908-7228 or go to their secure website www.sbtpg.com
https://ttlc.intuit.com/questions/2580357-who-provides-the-refund-processing-service
Also see this info