Estimated tax payments

If I pay 90% of taxes I owe by January 15, do I still pay penalty if those tax payments weren't paid every quarter?

posted

under the default underpayment of estimated tax method yes you would owe penalties since 1/4 is due each period. However, however, you do have the option of using the annualized income installment method on page 3 of the 2210 which might reduce or eliminate the penalties

it depends - if your income is "lumpy" and most was earned in the 4th quarter, then you may be okay to pay everything in January, 2025; but if your income is smooth or 'front end' loaded, then there is probably going to be a penalty.