When I checked a week ago, he IRS was still saying that the first quarterly estimate (2021 1040ES) was still due on 15 April.
Bottom of page 4:
"No extension is provided in this notice for the payment or deposit of any other
type of Federal tax, including Federal estimated income tax payments, or for the filing of
any Federal return other than the Form 1040 series and the Form 5498 series for the
2020 taxable year."
https://www.irs.gov/pub/irs-drop/n-21-21.pdf
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As to whether you will be penalized for paying the 1st Qtr 1040-ES late....that cannot be determined until you actually file and your entire 2021 income and tax situation becomes clear. As long as you double-pay for the 2nd qtr estimates...(i.e including the $$ to make-up what you missed), the penalty could be minimized ... but the exact details on that that won't be known (again) until you actually prepare and file next year.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
