If you overpay you get a refund on your tax return same as now. It all is combined on your return.
To prepare estimates for next year you need to be in your current return. You can just type W4 in the search box at the top of your return , click on Find. Then Click on Jump To and it will take you to the estimated tax payments section. Say no to changing your W-4 and the next screen will start the estimated taxes section.
OR go to
Federal on left
Other Tax Situations
Other Tax Forms
Form W-4 and Estimated Taxes - Click the Start or Update button
When you get to the W4 and Estimated Taxes section, say you want to adjust your income to go though all the screens.
