What form is typically used for filing corporate income tax?

Form 1120 is specifically designed for corporations to report their income, gains, losses, deductions, and credits, as well as to calculate their corporate taxes. This form is essential for domestic corporations and is used to report not only the income generated by the business but also other important financial information required by the IRS.

The significance of Form 1120 comes from its detailed requirements, which ensure that corporations provide a comprehensive picture of their financial activities over the tax year. This includes information about various types of income such as capital gains, as well as deductions for business expenses. The accurate completion of this form is crucial for determining the corporation's tax liability.

In contrast, other forms mentioned do not serve the same purpose. Form 990 is primarily used by tax-exempt organizations to provide the IRS with information about their operations, while Form 1040 serves individual taxpayers for personal income reporting. Form 1065, on the other hand, is for partnerships, detailing their income, deductions, and other financial aspects but is not applicable to corporations. Thus, Form 1120 is the appropriate choice for corporations filing income tax.