I'm doing my mother's taxes and trying to figure out her estimated taxes. My father died toward the end of 2023. So for 2023 my mother is filing a joint return as the surviving spouse. But for next year, 2024, she will be a single filer.
I suspect that she will probably have a higher taxable income, for various reasons having to do with RMDs, the lesser standard deduction, and some other investment related matters.
I'm trying to follow the 100% safe harbor rules for her estimated taxes. As I understand it, normally, one would just pay 100% of the current year's tax, in four payments, and that would protect one from penalities (even if my mother ends up owing more taxes than in the prior year).
However, in the IRS instructions for form 1040es (page 6), it states, in order to figure your prior years taxes as the basis for your estimated taxes: "If you filed a joint return for 2023 but you will not file a joint return for 2024, first figure the tax both you and your spouse would have paid had you filed separate returns for 2023 using the same filing status as for 2024. Then multiply the tax on the joint return by a fraction, the numerator being the tax you would have paid had you filed a separate return, over the total tax you and your spouse would have paid had you filed separate returns."
Having to refigure out my mother's taxes, as if she and my father had both filed separately in the past year would be a huge pain. Is this really necessary, in order to properly follow the safe harbor rules for estimated taxes? If so, why doesn't TurboTax do this for me? I thought this was the sort of thing TurboTax was supposed to help with? TurboTax knows my father died and my mother will be a single filer next year. But it doesn't seem to be following the stipulation I quoted from the IRS instructions.
