Underpayment

[chsuh]

I have underpaid my federal taxes (i.e. insufficient withholdings) for CY 2023.

All withholdings were via withholdings on my paychecks. I did NOT make any separate quarterly payments in 2023. 

It is now January 2nd, 2024. Can I make a payment now, for the CY 2023 tax year?

[Bsch4477]

Yes, you can but you still might owe a penalty since tax wasn’t paid throughout the year. 

[rjs]

Yes, you can make an estimated tax payment for 2023 until January 16, 2024. Make sure that you clearly designate the payment as being estimated tax for 2023.