IRS Form 1040 is the standard federal income tax form used by individuals in the United States to report their annual income. It allows taxpayers to calculate their tax liability, claim deductions and credits, and determine whether they owe additional taxes or are entitled to a refund. The form includes various sections for reporting income from different sources, such as wages, dividends, and self-employment. Taxpayers can also attach schedules for more complex situations, like business income or capital gains. Filing Form 1040 is essential for compliance with U.S. tax laws and is typically due by April 15 each year.