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

The 1040 is the federal income tax return form. You file it once a year to tell the IRS how much money you earned, what deductions or credits you can claim, and how much tax you owe or should receive back. It is the form most individual taxpayers use — whether you work as an employee, are self-employed, have investment income, or receive Social Security.

The IRS publishes a new 1040 each tax year (for the income you earned in the previous calendar year). The form itself is relatively short — usually one or two pages — but it pulls information from other documents and schedules you may need to file alongside it, depending on your situation.

Key Takeaways

  • The 1040 is the standard federal income tax return form that most individuals file once per year to report earnings and calculate what they owe or should receive back.
  • You report your total income on the 1040, then subtract deductions or claim credits to arrive at your final tax bill or refund.
  • Depending on your income sources, you may need to attach schedules like Schedule C (self-employment), Schedule D (investment gains), or Schedule 1 (other income) to your 1040.
  • The filing important date is usually April 15, though the IRS may extend it in some years; you can request an extension if you need more time.
  • You can file the 1040 by mail, through tax software, or with a tax professional — the IRS does not charge a fee to file.

What information goes on the 1040

The 1040 asks for your personal information at the top: your name, address, Social Security number, and filing status (single, married filing jointly, head of household, and so on). It then has sections for income, deductions, and credits.

In the income section, you report wages from an employer (taken from your W-2 form), interest and dividends, capital gains or losses, and any other income. If you are self-employed, you calculate your net profit on Schedule C and bring that number to the 1040. If you have rental income, investment losses, or other less common income sources, you report those on separate schedules and then transfer the totals to the 1040.

Below income, you claim either the standard deduction (a fixed amount that depends on your age and filing status) or itemized deductions (specific expenses like mortgage interest or charitable donations). You then explore any tax credits you may have access to for — such as the Earned Income Tax Credit or a child tax credit — which reduce your tax bill dollar-for-dollar.

When and how to file your 1040

You file your 1040 for the previous calendar year. For example, in 2024 you file a 1040 reporting the income you earned in 2023. The important date is usually April 15 of the following year, though the IRS sometimes extends this date. If you cannot meet the important date, you can request an automatic extension, which gives you until October 15 to file — but note that an extension to file is not an extension to pay, so you should estimate and pay any tax you owe by April 15 to avoid penalties and interest.

You have three main ways to file: by mail (printing the form and mailing it to the IRS address listed in the instructions), through tax software (many programs are free or low-cost), or with a tax professional such as a CPA or enrolled agent. The IRS does not charge a fee to file, though some tax software companies charge for their services and tax professionals charge for their time.

Schedules and forms that attach to the 1040

The 1040 itself is straightforward, but your full tax return may include additional forms depending on your income and situation. Common schedules include:

  • Schedule C — if you are self-employed or own a business, you report profit or loss here.
  • Schedule D — if you sold stocks, bonds, real estate, or other investments, you report capital gains or losses.
  • Schedule 1 — for other income such as alimony, unemployment benefits, or prizes.
  • Schedule A — if you itemize deductions instead of taking the standard deduction.
  • Schedule E — if you have rental income or income from partnerships or S corporations.

Your employer provides a W-2 form if you are an employee, and you use the numbers from it to fill in the wages section of your 1040. If you received interest or dividends, your bank or investment company sends you a 1099-INT or 1099-DIV. If you are self-employed, you receive 1099-NEC or 1099-MISC forms from clients who paid you. All of these documents inform what you report on the 1040.

The difference between the 1040 and other tax forms

The IRS publishes several versions of the 1040 for different situations. The main form is straightforward called the 1040. There is also the 1040-SR, designed for taxpayers age 65 and older, which has larger print and slightly different sections. Some taxpayers may use the 1040-NR if they are a nonresident alien.

Other tax forms — such as the 1040-ES (for estimated tax payments), 1040-X (to amend a return you already filed), or 1040-V (a payment voucher) — are related but serve different purposes. The standard 1040 is what you use to file your annual income tax return.

What happens after you file

After you file your 1040, the IRS processes it. If you are owed a refund, you receive it by mail or direct deposit (if you provided your bank account information). If you owe tax, you pay it by the important date or set up a payment plan with the IRS. The IRS may also contact you if they have questions about items on your return or if they audit you, though audits are uncommon for most taxpayers.

Keep a copy of your filed 1040 and all supporting documents for at least three years in case the IRS asks questions. If you file electronically, the tax software usually stores a copy for you.

Frequently Asked Questions

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

It depends on how much you earned and your filing status. The IRS sets a threshold each year — if your income is below that threshold, you are not required to file. However, if taxes were withheld from your paychecks or you may have access to for refundable credits like the Earned Income Tax Credit, filing may get you money back even if you are not required to file. Check the IRS website or your tax software for the current year's threshold.

Can I file a 1040 by hand, or do I have to use software?

You can file by hand. Print the form from the IRS website, fill it out, and mail it to the address in the instructions. Many people use tax software because it does calculations automatically and checks for errors, but there is no requirement to do so. If you mail a paper return, allow extra time for processing.

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

You can file an amended return using Form 1040-X. You must file it within three years of the original filing date. The amended return corrects the error, and you either pay additional tax owed or receive a refund for overpayment. You can file the 1040-X by mail or through some tax software.

Is there a penalty if I file my 1040 late?

Yes. If you file late and owe tax, the IRS charges a failure-to-file penalty and interest on the unpaid amount. If you cannot file by April 15, request an extension before the important date — this postpones the filing important date but not the payment important date. Paying what you estimate you owe by April 15 reduces penalties even if you file the actual return later.

Can I file a 1040 for a previous year if I did not file then?

Yes. You can file a prior-year 1040 at any time, though the longer you wait, the more interest and penalties may accumulate if you owe tax. If you are owed a refund, there is a time limit — generally you must file within three years to claim it. If you owe back taxes, the IRS may contact you; filing voluntarily is usually better than waiting.