We would like to do another Roth conversion later this year. We would like to wait until December, when we'll have a better idea of our taxes owed. We do not expect to qualify for the same safe harbor when filing our 2025 taxes, since the Roth conversion we did this year pushed our income so high.
We are thinking of doing estimated tax payments this year to cover the taxes on the Roth conversion later this year, and thus qualify for a safe harbor. Can the 4 estimated tax payments be made with unequal amounts? If the conversion is done in December, can most of the estimated tax be paid on the Q4 installment? Or would the IRS assess us an underpayment penalty because the Q1-Q3 payments were lower than the Q4 pament?
