The 1040 is the main form the IRS uses to collect your yearly income and calculate what you owe
The 1040 is the standard federal income tax form. You file it once a year to report all the money you earned, claim deductions and credits you're may have access to to, and tell the IRS whether you owe taxes or are due a refund. Almost every person who works in the United States files a 1040 or one of its shorter versions.
The form itself is one page, though you'll usually attach additional pages (called schedules) that break down specific income sources or deductions. The IRS uses what you report on the 1040 to verify that you've paid the right amount in taxes throughout the year — either through paycheck withholding or quarterly estimated payments if you're self-employed.
You file your 1040 between January 1 and April 15 each year, reporting income from the previous calendar year. The important date is April 15 unless that date falls on a weekend or holiday, in which case it moves to the next business day.
Key Takeaways
- The 1040 reports your total income for the year and calculates whether you owe federal income tax or are due a refund.
- You attach schedules to the 1040 depending on your situation — Schedule C if you're self-employed, Schedule A if you itemize deductions, Schedule D if you sold investments.
- The IRS compares what you report on the 1040 to what your employer or bank reported about you, so mismatches trigger audits.
- Filing by April 15 is required; filing early can speed up your refund if you're due one.
Who has to file a 1040
You must file a 1040 if your income exceeds a threshold set by the IRS each year. The threshold depends on your age, filing status (single, married, head of household), and whether you're claimed as a dependent. For 2024, a single person under 65 with earned income must file if they earned more than $14,600. A married couple filing jointly must file if their combined income exceeded $29,200.
Even if your income is below the threshold, you should file if you had taxes withheld from your paychecks or made estimated tax payments — you'll likely get a refund. Self-employed people must file if their net earnings from self-employment are $400 or more, regardless of other income.
The three versions of the 1040 and which one you use
The IRS offers three versions: the standard 1040, the 1040-SR (for people 65 and older), and the 1040-NR (for nonresidents). Most people file the standard 1040. The 1040-SR has larger print and slightly different line ordering but covers the same income and deductions. The 1040-NR is only for people who are not U.S. citizens and don't meet the substantial presence test.
All three versions are one page. The actual complexity comes from the schedules you attach, not from choosing between versions. A person with only W-2 wages and no deductions files a straightforward 1040 with nothing attached. A person with self-employment income, rental property, investment sales, and itemized deductions files the same 1040 but with five or six schedules behind it.
What income you report on the 1040
You report all income you received during the year: wages from a job (shown on your W-2), self-employment income, rental income, investment income (dividends, interest, capital gains), retirement distributions, and any other money you earned. The 1040 has specific lines for each type, and you add them up to get your total income.
Income you don't report includes gifts, inheritances, life insurance payouts, and money you borrowed. Certain types of income — like some interest from municipal bonds — are also excluded. If you're unsure whether something counts as income, the IRS website lists what does and doesn't.
Deductions and credits you can claim on the 1040
After you report your income, you subtract either the standard deduction or your itemized deductions, whichever is larger. The standard deduction for 2024 is $14,600 for single filers and $29,200 for married couples filing jointly. If you own a home with a mortgage, paid significant state and local taxes, or made large charitable donations, itemizing might save you more money — you'd use Schedule A to list those deductions instead.
After deductions, you claim credits, which directly reduce the tax you owe. Common credits include the Earned Income Tax Credit (EITC) if you have low to moderate income, the Child Tax Credit if you have children under 17, and the American Opportunity Credit if you paid college tuition. Credits are more valuable than deductions because they reduce your tax dollar-for-dollar rather than just reducing your taxable income.
How the 1040 calculates what you owe or what's due to you
The 1040 walks through a series of calculations. You start with your total income, subtract your deduction, and arrive at your taxable income. You then look up your tax in the IRS tax tables based on your taxable income and filing status. You subtract any credits you're may have access to to. Finally, you compare that number to the total amount withheld from your paychecks during the year (shown on your W-2) or the estimated taxes you paid.
If you withheld more than you owe, you get a refund. If you withheld less, you owe the difference. If they match exactly, you owe nothing and get nothing back. Most people get a refund because employers withhold more than necessary as a safety margin.
Schedules and forms you attach to the 1040
The 1040 itself is straightforward, but most people attach at least one additional form. Schedule C is for self-employed people reporting business income and expenses. Schedule A is for itemizing deductions instead of taking the standard deduction. Schedule D is for reporting capital gains and losses from selling stocks, bonds, or real estate. Schedule E is for rental income and losses.
You also attach your W-2 forms (one for each job) and 1099 forms (for self-employment, freelance work, interest, dividends, and other income sources). These forms are issued by your employer or the payer and are also sent to the IRS, so the IRS already knows about them. Mismatches between what you report and what was reported to the IRS are the most common reason for audits.
Where to file your 1040 and what happens after
You can file on paper by mailing your 1040 and schedules to the IRS address for your state (listed on the form itself), or you can file electronically using tax software or a tax professional. Electronic filing is faster and more accurate — the IRS processes e-filed returns in two to three weeks, while paper returns take six to eight weeks.
After you file, the IRS reviews your return for math errors and compares it to W-2s and 1099s reported by employers and payers. If everything matches, you're done. If the IRS finds a discrepancy, they'll send you a notice. If you're due a refund, it arrives by direct deposit or check within the timeframe above. If you owe and don't pay by the important date, the IRS charges interest and penalties.
Frequently Asked Questions
Can I file my 1040 before I receive all my W-2s and 1099s?
No. You need all W-2s and 1099s before you file because you must report all income. Employers and payers are required to send these forms by January 31. If you haven't received one by early February, contact the issuer directly. Filing without them and amending later costs time and risks penalties.
What if I made a mistake on my 1040 after I filed it?
You file an amended 1040 using Form 1040-X. You have three years from the original due date to file an amendment. If the mistake resulted in you overpaying, you'll get a refund. If you underpaid, you'll owe the difference plus interest and possibly penalties.
Do I need to keep my 1040 after I file it?
Yes. Keep your filed 1040, all schedules, W-2s, 1099s, and receipts supporting deductions for at least three years. The IRS can audit returns from the past three years, and you'll need these documents to prove what you reported. Keep them longer if you claimed a loss or didn't report income you should have.
What's the difference between the 1040 and the 1040-EZ?
The IRS discontinued the 1040-EZ after 2018. Everyone now files either the standard 1040 or the 1040-SR. The standard 1040 works for straightforward returns (just wages and standard deduction) and complex ones (self-employment, investments, itemized deductions) — you only attach the schedules you need.
Can I file my 1040 on my own, or do I need a tax professional?
You can file on your own using tax software (TurboTax, H&R Block, TaxAct) or by hand. Tax software walks you through each question and calculates your tax automatically. If your situation is straightforward — W-2 wages, standard deduction, no side income — software is usually sufficient. If you're self-employed, own rental property, or have complex investments, a tax professional can save you money by finding deductions and credits you might miss.