Form 1040

Form 1040, officially titled the U.S. Individual Income Tax Return, is an IRS tax form used by United States residents to file personal federal income tax returns. The form is used to calculate a taxpayer's total taxable income and to determine the amount of tax owed to or refundable from the federal government.

For individual taxpayers who follow the calendar year, income tax returns are generally due by Tax Day, which typically falls on April 15 of the following year. If April 15 falls on a Saturday, Sunday, or legal holiday, the due date is extended to the next business day. Taxpayers may obtain an automatic extension to file Form 1040 until October 15 by submitting Form 4868. However, this extension applies only to the filing deadline; any taxes owed must still be paid by the original due date to avoid penalties and interest.

Form 1040 consists of two pages (23 lines in total), not counting attachments. The first page collects information about the taxpayer(s) and dependents. In particular, the taxpayer's filing status is reported on this page. The second page reports income, calculates the allowable deductions and credits, figures the tax due given adjusted income, and applies funds already withheld from wages or estimated payments made towards tax liability. On the right side of the first page is the presidential election campaign fund checkoff, which allows individuals to designate that the federal government give $3 of the tax it receives to the presidential election campaign fund. Altogether, 142 million individual income tax returns were filed for the tax year 2018 (filing season 2019), 92% of which were filed electronically.