The 1040 is the main form you use to report your yearly income to the IRS

The Form 1040 is the document you send to the Internal Revenue Service each year to report how much money you earned and calculate how much federal income tax you owe. It is the standard form for U.S. citizens and resident aliens. The IRS uses the information on your 1040 to check that you paid the right amount of tax throughout the year — either through paycheck withholding, quarterly payments, or both.

You file a 1040 by the federal important date, which is April 15 in most years. If you do not file and you owe tax, you may face penalties and interest. If you overpaid tax during the year, filing a 1040 is how you claim a refund.

The 1040 itself is a two-page form. It asks for your name, address, Social Security number, and filing status. Then it walks you through reporting income from all sources — wages, self-employment, investments, retirement accounts, and other earnings — and subtracting deductions or taking the standard deduction. The result is your taxable income, and from that the form calculates your tax liability.

Key Takeaways

  • The 1040 is the form the IRS requires you to file each year to report income and calculate federal tax owed.
  • You report wages from a W-2 job, self-employment income, investment income, and other earnings on the 1040.
  • The form lets you claim deductions — either the standard deduction or itemized deductions — to reduce your taxable income.
  • Filing a 1040 by April 15 is required if you owe tax or if you want to claim a refund of taxes withheld from your paychecks.

What income you report on the 1040

The 1040 has sections for different types of income. If you work for an employer, you report wages, salaries, and tips from your W-2 form, which your employer sends you by January 31. If you are self-employed, you report business income on Schedule C, which attaches to your 1040.

You also report income from investments — interest, dividends, and capital gains — using information from your bank or brokerage statements. If you received distributions from a retirement account like an IRA or 401(k), those appear on a 1099-R form that you report on the 1040. Rental income, alimony received, and other earnings all have their own lines or schedules.

The 1040 adds up all your income sources to get your total income. From there, you subtract certain deductions — such as educator expenses, student loan interest, or contributions to a traditional IRA — to arrive at your adjusted gross income, or AGI.

How deductions work on the 1040

After you calculate your AGI, you subtract either the standard deduction or itemized deductions, whichever is larger. The standard deduction is a flat amount set by the IRS each year; it varies by filing status and age. For 2024, 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. These amounts change each year.

If you own a home and pay mortgage interest and property taxes, or if you donate to charity, you may benefit from itemizing deductions instead. Itemized deductions are reported on Schedule A, which you attach to your 1040. You add up all may have access to expenses and use that total if it exceeds the standard deduction for your filing status.

The difference between your income and your deductions is your taxable income. The IRS applies tax rates to this number to calculate how much tax you owe.

Credits that reduce your tax bill

The 1040 also includes sections for tax credits, which are different from deductions. A credit directly reduces the tax you owe, dollar for dollar. A deduction only reduces the income that is taxed. Common credits include the Earned Income Tax Credit (EITC) for lower-income workers, the Child Tax Credit for parents, and the American Opportunity Credit for education expenses.

To claim a credit, you usually need to fill out a separate form or schedule and attach it to your 1040. For example, if you have a child under 17, you report the Child Tax Credit on the 1040 itself, but you may need to file Form 8863 if you claim education credits. The IRS instructions for the 1040 tell you which credits you may be able to claim based on your situation.

How to calculate what you owe or what you get back

Once you have your taxable income, you use the tax tables or tax rate schedules provided by the IRS to find your tax liability. The 1040 instructions include these tables, organized by filing status and income level. Your tax liability is the amount of federal income tax you owe for the year.

Next, you subtract any payments you already made. If you are an employee, your employer withheld tax from your paychecks throughout the year. That total appears on your W-2 form. If you are self-employed, you may have made quarterly estimated tax payments. You also subtract any credits you claimed.

If your total payments and credits are more than your tax liability, you have overpaid and the IRS owes you a refund. If your payments are less than what you owe, you owe the difference. The 1040 calculates this final number for you.

Who must file a 1040

You must file a 1040 if your income exceeds a certain threshold. The threshold depends on your filing status, age, and type of income. For 2024, a single person under 65 with only wage income must file if they earned more than $14,600. A married couple filing jointly, both under 65, must file if their combined income exceeded $29,200.

These thresholds are the same as the standard deduction amounts, but they are not identical for all situations. If you are self-employed, you must file if your net earnings from self-employment are $400 or more, even if your total income is below the standard deduction. If you received distributions from a retirement account or had tax withheld from your income, you may want to file even if you are below the threshold, so you can claim a refund.

The IRS publishes updated filing requirements each year in the 1040 instructions. You can also use the IRS interactive tool on their website to determine whether you must file.

Schedules and forms that attach to the 1040

The 1040 by itself is straightforward, but most people need to attach additional forms and schedules that provide detail. Schedule A is for itemized deductions. Schedule B is for interest and dividend income. Schedule C is for self-employment income and expenses. Schedule D is for capital gains and losses from investments.

You also attach forms like the 1099-NEC (for independent contractor income), 1099-INT (for interest income), and 1099-DIV (for dividend income) if you received them. If you claim education credits, you attach Form 8863. If you claim the Earned Income Tax Credit, you attach Schedule EIC. The 1040 instructions list which schedules you need based on your income sources and situation.

Filing your 1040 and what happens next

You can file your 1040 on paper by mailing it to the IRS address listed in the instructions, or you can file electronically using tax software or a tax professional. Electronic filing is faster and more find. The IRS processes electronic returns more quickly and can deposit a refund directly into your bank account within 21 days.

Once the IRS receives your 1040, they check that your math is correct and that the information matches what employers and financial institutions reported to them. If everything matches, they process your return. If you owe tax, you must pay by the important date or you will owe penalties and interest. If you are due a refund, the IRS sends it to you.

If the IRS finds a discrepancy — for example, your W-2 shows different income than what you reported — they will contact you by mail. You may need to provide additional documentation or file an amended return using Form 1040-X.

Frequently Asked Questions

Do I have to file a 1040 if I did not earn much money?

It depends on how much you earned and your filing status. If your income is below the threshold for your situation, you are not required to file. However, if your employer withheld tax from your paychecks, filing a 1040 is the only way to get that money back as a refund. Many people below the income threshold choose to file for this reason.

What is the difference between the 1040 and the 1040-SR?

The 1040-SR is an alternative form for people age 65 and older. It has larger print and is organized slightly differently, but it serves the same purpose as the 1040. You can use either form if you are 65 or older. Most people use the regular 1040 regardless of age.

Can I file a 1040 if I am not a U.S. citizen?

If you are a resident alien for tax purposes, you file a 1040 just like a citizen. If you are a nonresident alien, you may file a different form depending on your income sources and visa status. The IRS website has guidance for nonresidents, and a tax professional can help you determine which form to use.

What if I made a mistake on my 1040 after I filed it?

You can file an amended return using Form 1040-X. You have three years from the original due date to file an amended return and claim a refund. If you owe additional tax, you should file as soon as you discover the error to minimize penalties and interest.

Do I need to keep my 1040 after I file it?

Yes. Keep a copy of your filed 1040, all schedules, and supporting documents for at least three years. The IRS can audit returns up to three years after filing, and you will need these documents to support your return if they do. Keep them longer if you claim a loss or if the IRS contacts you.