Where on turbotax do I enter the fact that I paid $20K to the IRS online in Feb. 2019 towards what I owe for capital gains in 2018?

[user4434474429 · Accepted solution]

You will be asked to log your April 15, June 15, September 15, 2018 estimated payments on a specific page under credits and taxes paid. You will also, at that time, be asked if you made an additional payment in 2019 for your 2018 taxes. You better have online documentation that you made that payment to be sure. You always need proof.

[Hal_Al]

In TurboTax (TT), enter at:
Federal Taxes Tab (Personal for H&B version)
Deductions & Credits
-Scroll down to:
--Estimates & other taxes paid
   -Estimates
Because the payment was made after Jan 15, do not enter the $20K as a 4th Qtr payment. Instead, click on "+Add another payment", at the bottom of the payment screen.

Be sure your Feb. payment was credited, by the IRS,  to your 2018 taxes and not treated as an estimated payment for 2019.