Pay by Bank is supported by 95% of US financial institutions. Supported financial institutions will appear when you create your Pay by Bank account. If your financial institution does not appear when you sign up for Pay by Bank, it is not supported.
Note!
If this is your first time signing up for Pay by Bank, and you receive the error message,"The linked financial institution is not supported. Please link a different bank account to Pay by Bank or select alternative payment method and retry." (Error code F102 or E001) then your financial institution is likely not supported.