interest charge for underpayment of estimated tax

[starfisht]

In 2024 I made an estimated state tax payment which was a little more than my state tax for 2023, but I didn't make the payment until the 3rd quarter of 2024. TT says that I owe interest for underpayment of estimated tax. I know that there should be no interest charged for underpayment of estimated tax if the estimated tax paid is at least equal to the tax of the previous year.

The only explanation that I can think of is that the estimated tax was not made until the 3rd quarter. Is that correct?

[SharonD007]

You can get hit with an underpayment penalty in the situation you described because you didn't pay the estimated quarterly taxes when they were due. You can contact your state to find out if they can reduce or eliminate the penalty.

You can visit your state’s Department of Revenue for more information.  Please review the TurboTax article How do I contact my state's Department of Revenue? for more information.

Here's a TurboTax article that may help you in the future: Why am I getting an underpayment penalty?