Form 1120: How to File the Forms

Filing taxes can be a complicated process, but having a better understanding of the forms your business needs to file can ease the stress of tax time. Here's what you need to know about Form 1120.

This article is for educational purposes and does not constitute legal, financial, or tax advice. For specific advice applicable to your business, please contact a professional. Nothing in this article constitutes tax or accounting advice. If you have questions about Form 1120, please consult a professional.

From car expenses to business lunches, there are many things to consider when it comes to tax time. In fact, a recent Capital One survey showed that 56% of small business owners listed taxes as their top concern for the year. Filing taxes can be a complicated process, but whether you are filing forms yourself directly through the IRS, using a tax software, or working with a tax professional, having a better understanding of the forms your business needs to file can ease the stress of tax time. 

What is Form 1120?

Form 1120 is a U.S. Corporation Income Tax Return form. It is used to report income, gains, losses, deductions, and credits, and to determine the income tax liability of a corporation. This is the tax form C corporations and LLCs use to file their income taxes. (If an entity with two or more members is formed as an LLC it is generally treated as a partnership.)

Unless exempt, all domestic corporations must file an income tax return whether or not they have taxable income. Unless you are a domestic corporation that is required (or elects) to file a special return, you must file Form 1120.

How do I file Form 1120?

Form 1120 can be filed online or by mail. You can file this form electronically using IRS Free File or a tax software if you feel comfortable filling out and filing this form yourself. Otherwise you can hire a professional tax preparer. The IRS also provides more detailed instructions around recent legislation and developments related to Form 1120.

Form 1120

Typically, a company must file its income tax return by the 15th day of the 4th month after the end of its tax year. There are, however, exceptions to this so be sure to refer to the latest IRS instructions form for more details. 

About the Form 1120 Series

There are several special forms related to Form 1120 that may be needed for your business. Below are a few that may be relevant:

  • 1120-C: U.S. Income tax return form used by cooperatives
  • 1120-H: U.S. Income tax return form used by condominium management, residential real estate management, and more
  • 1120-L: U.S. Income tax return form used by life insurance companies
  • 1120-S: U.S. Income tax return form used by S corporations