When completing the Q&A section for next year's Estimated Tax Payments, Form 1040-ES Estimated Tax for Individuals will compute the amount of your REQUIRED estimated tax payments, regardless of whether you select the worksheet calculation or to pay 100% of 2020 tax liability.

If you wish to pay additional amounts, you can modify your Total 2021 estimated tax:

1. From within your TaxAct return (Online or Desktop), click Federal. On smaller devices, click in the upper left-hand corner, then click Federal.
2. Click 2021 Estimated Tax Payments in the Federal Quick Q&A Topics menu, then click Yes.
3. Continue with the interview process to enter all of the appropriate information.
4. On the screen titled Federal 2021 Estimated Tax - Estimate Amounts, review your required estimated tax payments, enter the Total 2021 estimated tax amount you would like to pay, then click Continue twice for the amount to show as equally divided into four (4) quarterly payments.

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.