@Yevonnebowen wrote: Where is portal for direct deposit for stimulus
There is not a portal to update your bank account for the third stimulus.
IRS website for third stimulus FAQ's - https://www.irs.gov/coronavirus/get-my-payment-frequently-asked-questions#bank
If your bank information is invalid or the account has been closed, the bank will return your payment to the IRS and we will mail it to you by check at the address we have on file.
