Thank you for your reply, I think I have to wait for another bill from IRS. I also assume that the answer to my actual question is: "TurboTax does not support entering correct penalty and interest even when I know the exact numbers". Both numbers are not very difficult to get from IRS calculator.
This is disappointing. By the time IRS will bill me, additional fees will likely accumulate. It further means that TurboTax makes it impossible to file extended tax report at once -- I need to wait for additional bill from IRS and make another payment before I can declare taxes completed.
