Form 1040 is the primary document used by individuals to file their U.S. federal income taxes with the Internal Revenue Service (IRS). Known officially as the “U.S. Individual Income Tax Return,” the 1040 form is where taxpayers report their annual income, claim deductions and tax credits, and determine whether they owe additional taxes or qualify for a refund. This form must be submitted annually — typically by April 15 — and it serves as the foundation of federal tax reporting. Form 1040 has several accompanying schedules depending on your financial situation, such as reporting self-employment income, capital gains, or itemized deductions. Whether you are employed full-time, freelance, or receive investment income, nearly every taxpayer must fill out a version of this form. Mastery of Form 1040 is crucial for responsible tax planning, avoiding penalties, and ensuring you're not overpaying or underreporting income. It is essentially the centerpiece of individual income tax compliance in the United States.