The 1040 is the main form you use to report your income to the IRS
The 1040 is the federal income tax return form that most individual taxpayers file with the Internal Revenue Service each year. It asks for your personal information, lists all the income you earned during the tax year, shows deductions and credits you can claim, and calculates how much tax you owe or how much of a refund you should receive.
You file a 1040 because federal law requires anyone with income above a certain threshold to report it. The IRS uses your 1040 to verify that you paid the correct amount of tax. If your employer withheld too much from your paychecks, the 1040 determines your refund. If you withheld too little, it calculates what you still owe.
The 1040 itself is a two-page form. It does not stand alone — you attach supporting documents called schedules that provide details about specific types of income, deductions, or credits. For example, if you have investment income, you attach Schedule B. If you own a business, you attach Schedule C. These schedules feed information into the main 1040 form.
Key Takeaways
- The 1040 is a two-page federal form where you report all income, claim deductions and credits, and calculate your total tax liability or refund.
- You file a 1040 if your income exceeds the threshold set by the IRS for your filing status, which changes each year.
- Schedules are separate forms you attach to your 1040 to report specific income types, deductions, or credits in detail.
- The IRS uses your 1040 to match what you report against what employers, banks, and other payers reported about you.
What income you report on the 1040
The 1040 asks you to list all income you received during the tax year. This includes wages from an employer, self-employment income, interest from savings accounts, dividends from investments, capital gains from selling stocks or property, rental income, and income from side work or freelance projects.
Not all income is taxable. For example, gifts and inheritances are generally not reported on a 1040. Municipal bond interest is also usually excluded. But the form itself does not make these distinctions — you report what you earned, and the instructions and schedules guide you on what to include or exclude.
If you have income from multiple sources, each one may require a different schedule. W-2 wages go on the main 1040. 1099 income from freelance work, consulting, or other self-employment goes on Schedule C. Interest and dividends go on Schedule B. The 1040 then pulls the totals from all these schedules to calculate your total income.
Deductions and credits you can claim
The 1040 gives you two paths to reduce the tax you owe: deductions and credits. A deduction reduces the amount of income that is subject to tax. A credit reduces the tax itself, dollar for dollar.
You can take either the standard deduction or itemized deductions, but not both. The standard deduction is a flat amount that depends on your filing status and age. For the 2024 tax year, the standard deduction ranges from $14,600 for a single filer under 65 to $29,200 for a married couple filing jointly, both under 65. If you have large deductible expenses — mortgage interest, state and local taxes, charitable donations — you may benefit from itemizing instead, which requires Schedule A.
Credits are separate from deductions. Common credits include the Earned Income Tax Credit, the Child Tax Credit, and the American Opportunity Credit for education expenses. Each credit has its own rules and may require a separate schedule or form to claim it.
How the 1040 calculates what you owe or your refund
The 1040 follows a step-by-step calculation. You add up all your income from all sources. You subtract either the standard deduction or your itemized deductions. The result is your taxable income. You then use the tax tables provided by the IRS to find the tax on that income.
Next, you subtract any credits you are may have access to to claim. This gives you your total tax liability — the amount you owe to the federal government for the year.
Then the 1040 accounts for what you already paid. If you had a job, your employer withheld federal income tax from each paycheck and sent it to the IRS. If you are self-employed or have investment income, you may have made estimated tax payments throughout the year. The 1040 subtracts these payments from your total tax liability. If you paid more than you owe, you get a refund. If you paid less, you owe the difference.
The difference between the 1040 and other tax forms
The IRS offers a simplified version called the 1040-SR for taxpayers age 65 and older. It has larger print and a slightly different layout, but it covers the same income and deductions as the regular 1040.
Before 2018, the IRS offered the 1040-A and 1040-EZ as simpler alternatives for taxpayers with straightforward situations. These forms no longer exist. Now, all individual taxpayers use the 1040, though you may not need to file a 1040 at all if your income is below the filing threshold for your situation.
Schedules are not separate tax forms in the sense that you do not file them with a different agency. They are attachments to the 1040 that provide supporting detail. You file the 1040 and all relevant schedules together as one package to the IRS.
When you file your 1040 and where it goes
The tax year runs from January 1 to December 31. You file your 1040 by April 15 of the following year, unless that date falls on a weekend or holiday, in which case the important date moves to the next business day. The IRS sometimes grants an automatic extension that moves the important date to October 15, but this extension applies only to filing — you still owe any tax due by April 15.
You can file your 1040 on paper by mail or electronically through the IRS website or through tax software. Paper returns go to an IRS processing center. Electronic returns are processed faster and are less likely to have errors flagged for review.
You keep a copy of your 1040 and all schedules for your records. You do not send supporting documents like W-2s or receipts with your return, but you must keep them in case the IRS asks to see them later.
Who must file a 1040
You must file a 1040 if your income exceeds the filing threshold for your filing status. The threshold changes each year and depends on whether you are single, married filing jointly, married filing separately, head of household, or may have access to widow or widower. For 2024, a single person under 65 must file if their income is $14,600 or more. A married couple filing jointly, both under 65, must file if their combined income is $29,200 or more.
Even if your income is below the threshold, you may want to file if you had taxes withheld from your paychecks or made estimated payments. Filing allows you to claim a refund of the money you overpaid.
Self-employed people must file if their net self-employment income is $400 or more, regardless of other income. This is because self-employment tax — Social Security and Medicare tax — applies at a lower threshold than income tax.
Frequently Asked Questions
Can I file a 1040 if I have very little income?
Yes. If you had any income and taxes were withheld, filing a 1040 may result in a refund. Even if you are below the filing threshold, you can file to claim refundable credits like the Earned Income Tax Credit, which can result in a payment to you even if you owe no tax.
What happens if I file my 1040 late?
If you file after April 15, you may owe a failure-to-file penalty and interest on any tax you owe. If you are owed a refund, there is no penalty, but you lose the refund if you do not file within three years. Filing an extension form by April 15 moves your important date to October 15 and avoids the penalty.
Do I need to file a 1040 if I only have Social Security income?
Usually not. Social Security benefits are generally not taxable unless you have other income. However, if you have income from work or investments in addition to Social Security, you may need to file. The rules depend on your total income and filing status.
What is the difference between a schedule and a form?
A form is a standalone document you file with the IRS, like the 1040 itself. A schedule is a supporting document you attach to a form to provide detail about a specific item. For example, Schedule C reports self-employment income and is attached to your 1040.