Form 1120 and 1120S due dates

Chicago Small Business Accountant

Updated July 23, 2015
Form 1120 and 1120S due dates

The Corporation Income Tax Return (Form 1120) is due 75 days after the established year end of the company. If the company closes its books on December 31st, then the return is due by March 15th of the following year. If the company’s year end is July 31st, then the return is due 75 days after that, or no later than October 15th.

Income tax forms

What happens if you can’t file your return promptly, and you file an extension? If you file Form 7004, it provides an automatic 6 month extension to file the income tax form only. It does not provide an extension for any money which may be owed. If you are going to owe money with the tax return after including any estimates which were made, then you will have to make a deposit with the extension. If you do not, then you will end up paying penalties once the return is filed.


As you may or may not know, there are usually no taxes due with the federal S-Corp returns, or Form 1120S. This return may be extended without a tax deposit because no tax will probably be due. The income tax for The State of Illinois is a different matter. If you are extending, you may need to make a deposit for the state.


If you are asking these questions in the first place, then it’s time for a new accountant.
If you are having problems with your Form 1120 and 1120S due dates or have issues with your accounting in general, we would love to help. I enjoy hearing from my readers, and can be contacted at
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Chris Amundson is the President of Accounting Solutions Ltd., a full service public accounting firm of Certified Public Accountants and Enrolled Agents handling the bookkeeping, accounting, tax preparation, and audit representation needs of Businesses, Estates, Trusts, and Upper Income Individuals.

Chris Amundson is President of Accounting Solutions Ltd. located in Chicago, Illinois

Chicago Accounting Firm & Tax Solutions for Small Businesses

Last updated on July 31, 2015
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