The Form 1040 is the main tax return form the IRS uses to collect income tax from individuals

Form 1040 is the document you send to the IRS each year to report how much money you earned and how much tax you owe. The IRS uses it to match your reported income against what employers, banks, and other payers have already reported about you. If you earned income in the previous year — whether from a job, self-employment, investments, or other sources — you will likely need to file this form or a related version of it.

The form itself is relatively short: the main page is one or two sheets, depending on your situation. But it connects to schedules and worksheets that handle specific types of income or deductions. Most people file Form 1040 because their employer withheld taxes from their paychecks throughout the year, and the form is how they report whether too much or too little was taken out.

Key Takeaways

  • Form 1040 reports your total income for the year and calculates how much federal income tax you owe or should receive back as a refund.
  • You must file if your income exceeds a threshold that changes each year based on your age and filing status — for example, $13,850 for a single person under 65 in 2023.
  • The form requires your Social Security number, filing status, income from all sources, and information about dependents if you claim any.
  • You can file Form 1040 on paper by mail or electronically through tax software or a tax professional, and electronic filing is faster and more accurate.
  • The IRS deadline to file is usually April 15, though you can request an extension that gives you until October 15 to submit your return.

Who has to file Form 1040

You must file if your income for the year is above a certain threshold. That threshold depends on your age, filing status, and type of income. For 2023, a single person under 65 with only wage income had to file if they earned $13,850 or more. A married couple filing jointly with both under 65 had to file if they earned $27,700 or more. These numbers change each year, and they are higher if you are 65 or older.

Even if your income is below the threshold, you should file if you had taxes withheld from your paychecks or made estimated tax payments during the year. Filing allows you to claim a refund of the money the IRS held. You should also file if you are claiming dependents or certain tax credits, because those can reduce what you owe or increase your refund.

Self-employed people must file if their net earnings from self-employment were $400 or more, even if their total income is below the wage threshold. If you had investment income, rental income, or other sources beyond wages, different rules may apply.

What information you need to gather before filing

Start by collecting documents that show your income. If you worked for an employer, you will receive a W-2 form by January 31 showing your wages and taxes withheld. If you had other income — interest from a bank, dividends from investments, income from a side business — you will receive forms like a 1099-INT, 1099-DIV, or 1099-NEC reporting those amounts.

You will also need your Social Security number, your spouse's Social Security number if filing jointly, and Social Security numbers for any dependents you claim. Have your filing status ready: single, married filing jointly, married filing separately, head of household, or may have access to widow or widower. If you own a home and paid mortgage interest or property taxes, gather those statements. If you made charitable donations, keep a record of those amounts.

If you paid for childcare, education, or health insurance, or if you had student loan interest, gather those documents too. The more organized you are before you start, the faster the filing process moves.

How Form 1040 connects to schedules and other forms

Form 1040 itself is the summary page. Depending on your situation, you attach additional forms and schedules that break down specific types of income or deductions. For example, if you are self-employed, you file Schedule C to report your business income and expenses, then transfer the net profit to Form 1040. If you have investment income, you file Schedule B to list interest and dividends, then report the total on the main form.

If you claim itemized deductions instead of the standard deduction, you file Schedule A to list mortgage interest, property taxes, charitable donations, and other deductible expenses. If you have dependents, you list them on Form 1040 itself, but if you claim certain credits like the Earned Income Tax Credit, you may need to file Schedule EIC or other supporting forms.

The IRS instructions that come with Form 1040 tell you which schedules you need based on your income and situation. Tax software typically guides you through this automatically, asking questions and generating the right forms for you.

Where to file and how to submit your return

You have two main options: file electronically or file on paper by mail. Electronic filing is faster, more accurate, and you receive confirmation that the IRS received your return. You can file electronically through tax software (like TurboTax, H&R Block, or TaxAct), through a tax professional, or through the IRS Free File program if your income is below a certain threshold.

If you file on paper, print Form 1040 and any schedules, sign and date the return, and mail it to the IRS address listed in the instructions. That address varies by state. Paper returns take longer to process — typically 21 days or more — and errors are caught more slowly.

The deadline to file is usually April 15 of the year following the tax year. If April 15 falls on a weekend or holiday, the deadline moves to the next business day. You can request an automatic extension by filing Form 4868, which gives you until October 15 to file, but it does not extend the deadline to pay taxes owed.

What happens after you file Form 1040

After you submit your return, the IRS processes it. If you filed electronically, the IRS typically acknowledges receipt within 24 hours. The actual processing takes longer — usually 21 days for electronic returns and several weeks for paper returns. During this time, the IRS checks that your reported income matches what employers and other payers reported about you.

If everything matches and you are owed a refund, the IRS deposits it into your bank account or mails you a check, depending on how you requested it. If you owe additional tax, the IRS sends you a bill. If there is a discrepancy — for example, your reported income does not match a W-2 — the IRS sends you a notice asking for clarification.

Keep a copy of your filed return and all supporting documents for at least three years. The IRS can audit a return up to three years after filing, or longer if they suspect underreporting of income.

Form 1040 versus other versions and alternatives

The IRS offers simplified versions of Form 1040 for people with straightforward tax situations. Form 1040-SR is designed for people 65 and older and has larger print and a simpler layout, though it covers the same income and deductions as the regular 1040. Form 1040-NR is for nonresident aliens with U.S. income.

If your situation is very simple — you have only wage income, no dependents, and no itemized deductions — you might have been able to use Form 1040-EZ in past years, though the IRS discontinued that form after 2017. Now all filers use Form 1040, though the form itself adapts based on what you report.

Some people do not file Form 1040 at all because they do not meet the income threshold and have no reason to file. Others use tax software that generates the form automatically without them seeing the paper version. The form itself is a tool; what matters is that your income is reported to the IRS accurately.

Frequently Asked Questions

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

Only if your income is above the threshold for your filing status and age. But if you had taxes withheld from paychecks or made estimated payments, you should file to get a refund. You should also file if you claim dependents or tax credits.

What is the difference between Form 1040 and a W-2?

A W-2 is a form your employer sends you showing what you earned and what taxes were withheld. Form 1040 is what you file with the IRS to report all your income from all sources and calculate your total tax. You use the W-2 to fill out Form 1040.

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

You can file by hand and mail it to the IRS, but electronic filing is faster and more accurate. If you have a simple return, free tax software is available through the IRS Free File program. A tax professional can also file for you.

What if I make a mistake on Form 1040 after I file it?

You can file an amended return using Form 1040-X. You have three years from the original filing date to file an amendment. If the IRS finds an error, they will send you a notice and bill or refund accordingly.

Do I need to file Form 1040 every year?

Only if your income exceeds the threshold or you have a reason to file, like claiming credits or getting a refund. Once you stop meeting the filing requirement, you do not have to file unless your situation changes.