Thanks for your replies. However, my original post wasn’t very clear, and, as a result, I think some people misunderstood the issue I was trying to raise.
My concern is about the Estimated Taxes calculation in the Other Tax Situations section. In completing that section, I first answered page after page of questions about next year’s expected income, deductions and credits so that Turbo-tax could calculate next year’s expected taxable income and the associated tax. This is exactly what I would expect it to do, and those calculations appear to be correct since Turbo-Tax’s results agree with the results that I arrived at independently.
However, from that point, things seem to go astray. To simplify matters, let’s assume that I prefer to have estimated taxes calculated so that at the end of the year I will have paid 100% of my expected 2026 taxes (as opposed to, e.g., 110% of 2025 taxes). In order to calculate the amounts for the expected tax vouchers I would expect Turbo-Tax to next determine how much is already* planned to be withheld, and to then prepare vouchers to cover roughly the difference between the expected 2026 total tax and the amount already planned to be withheld. This is where things seem to fall apart. Especially:
- It asks only about tax payments that you have already* made, but not about amounts that you have planned to withhold in the future. For example, a retiree might plan to take all of the Required Minimum Distributions from his IRA in October and have some tax withheld. I could be wrong, but it seems to me Turbo-Tax used to do a better job here. I have used the vouchers fairly often in the past, and have generally found the amounts to be at least in the correct ballpark. My recollection is that there used to be an opportunity to input planned future withholdings; @SCswede agrees. Without those, your best assumption is to extrapolate the past into the future - which would often be incorrect unless all of your income is from a paycheck or monthly pension.
- Even worse, as best I can tell, the entry in the "Federal Tax Withheld already" field is totally ignored anyway! Turbo-Tax prepares the same vouchers whether I say I’ve withheld $0 year-to-date or $20,000! Something is clearly wrong. If someone blindly trusted these results it could result in a horrendous overpayment of taxes or, worse, their being unable to pay their taxes next April.
Finally, the rounding calculation on the vouchers is incorrect. At one point I selected “round to nearest $10” and the resulting vouchers were for $2120 each. When I selected “round to nearest $100” the resulting vouchers were for $2200 each! Needless to say, that is not the nearest $100; it is rounding up. A small thing I’ll admit, but an unnerving result from an app that you are counting on to be "good a math"….
None of this is insurmountable for me since I also have a spreadsheet that does these calculations. I'm just disappointed in Turbo-Tax, and also concerned that someone less careful might blindly use these vouchers and get in trouble.
