The standard Internal Revenue Service (IRS) form that individuals use to file their annual income tax returns. The form contains sections that require taxpayers to disclose their financial income status for the year in order to ascertain whether additional taxes are owed or whether the taxpayer is due for a tax refund. 1040 forms need to be filed with the IRS by April 15.

Also known as the "U.S. individual income tax return" or the "long form".

While the 1040 form is composed of only a couple of pages, taxpayers may need to fill out extra sections called schedules. For example, if a taxpayer received dividends that totaled more than $1,500, he or she will need to fill out Schedule B, which is the section for reporting interest and ordinary dividends.

There are several variations of the 1040 depending on your individual tax situation. For example, taxpayers that possess very simple taxation circumstances can fill out the Form 1040EZ, which is a less comprehensive form.