Form 1040U.S. Individual Income Tax Return
The main federal tax return form that every individual filer uses. All income, deductions, credits, and tax calculations flow through this form.
Who needs to file this form
You must file a Form 1040 if your gross income exceeds the filing threshold for your filing status ($16,100 for single filers under 65 in 2026, $32,200 for married filing jointly). Even if your income is below the threshold, you should file if you had tax withheld (to get a refund) or are eligible for refundable credits like the EITC or Additional Child Tax Credit.
Key Deadlines
Filing deadline
April 15, 2027
For 2026 tax year returns
Extension deadline (Form 4868)
October 15, 2027
Extension to FILE only -- you must still PAY by April 15
Amend a return (Form 1040-X)
Within 3 years of original filing
Step-by-Step Filing Guide
Gather all income documents
Collect every W-2, 1099-NEC, 1099-INT, 1099-DIV, 1099-B, 1099-K, 1099-DA, and any other income statements. The IRS receives copies of all these forms -- missing income is the #1 audit trigger.
Choose your filing status
Select from: Single, Married Filing Jointly, Married Filing Separately, Head of Household, or Qualifying Surviving Spouse. Your status as of December 31 determines your filing status for the entire year.
Calculate total income (Lines 1-9)
Enter all income sources: wages (Line 1), interest (Line 2), dividends (Line 3), capital gains (Line 7), business income from Schedule C (Line 8), and other income. Total income appears on Line 9.
Apply adjustments to get AGI (Lines 10-11)
Subtract above-the-line deductions: educator expenses, HSA contributions, self-employment tax deduction, IRA deductions, student loan interest. Your AGI on Line 11 is the most important number -- it determines eligibility for many credits.
Take the standard deduction or itemize (Line 12-13)
For 2026: standard deduction is $16,100 (Single), $32,200 (MFJ), $24,150 (HoH). Only itemize on Schedule A if your deductions exceed the standard amount. About 89% of filers take the standard deduction.
Calculate tax and apply credits (Lines 14-24)
Compute your tax from the tax tables or qualified dividends worksheet. Apply credits: Child Tax Credit, education credits, EITC, etc. Subtract withholding and estimated payments. Line 37 shows your refund; Line 37 shows amount owed.
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