There is no way to update your banking information for this round of stimulus payments. The IRS says: The IRS cannot change payment information, including bank account or mailing information. If an eligible taxpayer does not get a payment or it is less than expected, it may be claimed on the 2020 tax return as the Recovery Rebate Credit.
If you didn’t receive the stimulus payments or the correct amount of stimulus payments, you can claim the Recovery Rebate Credit when you file your 2020 taxes and it will provide the same amount of payment as the stimulus would have. TurboTax will guide you through this when you prepare your return.
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