You can mail it and have a postmark of February 1.
Payment Due Dates You can pay all of your estimated tax by April 15, 2020, or in four equal amounts by the dates shown below.
1st payment . April 15, 2020
2nd payment June 15, 2020
3rd payment Sept. 15, 2020
4th payment Jan. 15, 2021*
* You don’t have to make the payment due January 15, 2021, if you file your 2020 tax return by February 1, 2021, and pay the entire balance due with your return.
