When completing the Q&A section for next year's Estimated Tax Payments, Form 1040-ES will compute the amount of your REQUIRED estimated tax payments, regardless of whether you select the worksheet calculation or to pay 100% of 2017 tax liability.
If you wish to pay additional amounts, you can modify your Total 2018 estimated tax:
- From within your TaxAct® return (Online or Desktop), click on the Federal tab. On smaller devices, click in the upper left-hand corner, then select Federal
- Click 2018 Estimated Tax Payments
- Click Yes to review the requirements for making estimated tax payments
- Continue to the screen titled Federal 2018 Estimated Tax - Estimate Amounts to review your required estimated tax payments.
- Enter the Total 2018 estimated tax amount you would like to pay
- Click Continue twice and the amount will show as equally divided into four (4) quarterly payments.