What is IRS Form 1040
IRS Form 1040 is the standard federal income tax return used by U.S. individuals — it's where you report your income, claim deductions and credits, and calculate whether you owe taxes or are owed a refund.
IRS Form 1040, officially titled U.S. Individual Income Tax Return, is the primary document used to file your federal income taxes each year. Almost every individual taxpayer in the United States uses Form 1040 to report income, calculate their tax liability, claim deductions and credits, and determine whether they owe additional taxes or are entitled to a refund.
Starting with 2018, the IRS consolidated the previous 1040, 1040A, and 1040EZ forms into a single streamlined Form 1040. Complexity is now handled through numbered schedules attached to the core form.
How Form 1040 Is Organized
The core form works like a funnel — starting with total income and progressively subtracting deductions to arrive at taxable income, then applying the tax brackets, then applying credits:
- Personal information — name, address, Social Security numbers, filing status
- Dependents — qualifying children and other dependents
- Income — wages, interest, dividends, retirement, business income, other (many pulled from Schedule 1)
- AGI calculation — total income minus above-the-line deductions
- Standard or itemized deduction — whichever you choose
- Taxable income — AGI minus deduction
- Tax calculation — based on tax brackets
- Credits — reduce tax owed dollar-for-dollar
- Other taxes — self-employment tax, AMT, etc.
- Payments — taxes already withheld or prepaid
- Refund or amount owed
Key Form 1040 Schedules
When your tax situation goes beyond wages and simple deductions, you'll attach numbered schedules:
| Schedule | Purpose |
|---|---|
| Schedule 1 | Additional income (freelance, rental, alimony) and above-the-line deductions |
| Schedule 2 | Additional taxes (AMT, self-employment tax, household employment taxes) |
| Schedule 3 | Additional credits (foreign tax credit, education credits, child/dependent care) |
| Schedule A | Itemized deductions |
| Schedule B | Interest and ordinary dividends over $1,500 |
| Schedule C | Profit/loss from business (sole proprietors) |
| Schedule D | Capital gains and losses |
| Schedule E | Supplemental income from rental real estate, partnerships, S corps |
| Schedule SE | Self-employment tax calculation |
Important Lines to Know
- Line 1: Wages, salaries, tips (from W-2)
- Line 11: Adjusted Gross Income (AGI)
- Line 12: Standard or itemized deduction
- Line 15: Taxable income
- Line 24: Total tax
- Line 33: Total payments (withholding + estimated tax + credits)
- Line 35: Refund amount (if line 33 > line 24)
- Line 37: Amount owed (if line 24 > line 33)
When Form 1040 Must Be Filed
Generally, you must file if your gross income exceeds a threshold based on filing status and age. For 2025:
- Single under 65: $15,000
- Married filing jointly (both under 65): $30,000
- Head of household: $22,500
- Self-employed: $400 in net profit (regardless of other income)
Even if you're below these thresholds, you should file if taxes were withheld from your income, since filing is how you claim a refund.
Filing Deadline
The standard deadline to file Form 1040 is April 15. If that falls on a weekend or holiday, the deadline shifts to the next business day. You can file for an automatic 6-month extension (to October 15) using Form 4868, but an extension to file is not an extension to pay — any tax owed is still due by April 15.