IRS states if you file by Feb 1, 2021 and don't owe taxes you can skip Q4 estimated tax payment. Since IRS isn't accepting returns until Feb 12, how does this work?

If you have no payment due on your tax return, it doesn't matter that you skipped the Q4 estimated tax payment, even if you don't file until after Feb. 12. You're not required to make four payments as long as you paid enough in total to cover all your tax for the year.

Thank you! Seems kind of obvious as I read your answer. The IRS language that confused me: "* 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." I somehow missed the last phrase about the deadline applying only if I have a balance due.

What if you owe taxes? Was this Feb 1,2021 deadline extended since tax season only starts Feb 12?

You can skip the final payment if you will file your return and pay all the tax due by February 1. If not, the IRS assumes that you had the income throughout the year and simply underpaid your estimated tax.

Thank you. But since the IRS isn't accepting tax returns before February 12, if I don't owe any taxes and file by then, is it okay not to pay Q4 estimated taxes?

if you don't need to make the 4th qtr estimate because you are already overpaid, you don't have to pay.

No underpayment of estimated tax penalty if:
1) Taxes less withholding leaves a balance due of less than $1,000
2) Timely tax payments, estimates and withholding, equal or exceed 90% of 2020 tax
3) Timely tax payments. estimates and withholding, equal or exceed 100% of your prior year tax (110% if your prior year adjusted gross income was over $150,000)