Everything you need to know about Form 1120

What is Form 1120?

Form 1120 is the U.S. Corporation Income Tax Return — the federal return filed annually by every domestic C corporation, regardless of whether the corporation has taxable income. The form reports gross receipts, costs, deductions, credits, and the corporation's tax liability for the year. C corporations are taxed at the entity level under Subchapter C of the Internal Revenue Code, separate from their shareholders.

Who must file Form 1120?

Every domestic corporation organized in the United States and treated as a C corporation must file Form 1120, even if it had no taxable income for the year. This includes newly incorporated entities that haven't yet started business, dissolved corporations filing a final return, and corporations operating at a loss. S corporations file Form 1120-S instead; partnerships file Form 1065.

What you'll need to complete it?

Have your corporation's financial statements (income statement and balance sheet), payroll records, depreciation schedules, prior-year tax return, and documentation for any credits or special deductions claimed (research credit, foreign tax credit, section 179, and so on). You'll also need EIN, incorporation date, and information for any shareholders, officers, and related parties required by the form's schedules.

When and how to file?

Form 1120 is due on the 15th day of the fourth month after the corporation's tax year ends — April 15 for calendar-year filers. Corporations with a fiscal year ending June 30 have a special September 15 deadline. File electronically through the IRS Modernized e-File (MeF) system or mail to the service center listed in the Form 1120 instructions. Most corporations with $10 million or more in assets are required to e-file.