If your corporation follows a calendar year, your estimated corporate tax payments are due April 15, June 15, September 15, and December 15. If the date falls on a Saturday, Sunday, or legal holiday, payment is due the next business day.

If you have completed your tax return, locate your estimated tax due in TaxACT by following these steps:

1. Start the TaxACT Business 1120 program
2. Click the gray Forms button in the tool bar and select Form 1120-W - Estimated Tax for Corporations
3. Scroll to the bottom of Form 1120-W for due dates and estimated tax due. Pay your estimated taxes online for free through the Electronic Federal Tax Payment System (EFTPS), or arrange for payment through a financial institution, payroll service, or other trusted third party.

If you have not completed your tax return, calculate your estimated tax due by following these steps:

1. Start the TaxACT Business 1120 program
2. Click on the Federal Q&A tab, then select 2015 Estimated Tax Payments
3. Simply answer the questions to calculate your estimated tax due. Pay your estimated taxes online for free through the Electronic Federal Tax Payment System (EFTPS) or arrange for payment through a financial institution, payroll service, or other trusted third party.

See the IRS Instructions for Form 1120-W for additional information about making estimated tax payments.

Note: If you are an S corporation expecting to owe federal tax of $500 or more on your 1120S return, you may be required to make estimated tax payments. S corporations traditionally do not pay income tax. However, if you are a pass-through entity, you may be required to pay tax on LIFO (last in first out) recapture, capital gains, or built-in gains. For more information, see the IRS Instructions for Form 1120S.