If you filed jointly in 2021 or 2022 but not both years and you transferred in your 2021 tax return to begin your 2022 tax return, TurboTax will automatically generate Form 2210 to mark Box E if the it's necessary to use the 2021 to liability to determine any penalty you might owe (because the correct amount for line 8 is smaller than line 5). If you did not transfer in your 2021 tax return, in the underpayment penalty section you must indicate your differing filing status and enter the appropriate amount for your 2021 tax liability so that TurboTax will mark Box E and prepare Form 2210 Part I correctly.
With regard to marking box E, if you filed jointly in 2022 but not in 2021, the amount to be used on line 8 of Form 2210 is the sum of your 2021 tax liability (or possibly 110% of that) plus your spouse's 2021 tax liability (or possibly 110% of that). If you transferred in the 2021 tax return to begin your 2022 tax return, TurboTax will transfer only transfer in your own 2021 tax liability. After you indicate that you are filed separately or single for 2021 you must adjust the tax liability carried in from the 2021 tax return to add your spouse's share. The Learn More link in the underpayment section provides instructions for doing this. Of course if you prepared your 2022 tax return without transferring in the 2021 tax return, you simply enter the combined tax liability rather than having to modify the amount TurboTax carried in.
