What the 1040 Tax Form Is and Who Files It

The 1040 is the main form you use to report your income and calculate what you owe in federal taxes

Form 1040 is the U.S. individual income tax return. It is the form most people file with the IRS each year to report their wages, investment income, self-employment earnings, and other money they received. On the 1040, you list your income, claim deductions or the standard deduction, and calculate your tax liability — the amount you owe or the refund you should receive.

The IRS uses the 1040 to match what you report against what employers, banks, and other payers reported about you on forms like the W-2 and 1099. If you received income during the year, you almost certainly need to file a 1040 or a simpler variant of it.

The 1040 comes with two schedules that most filers attach: Schedule A (if you itemize deductions instead of taking the standard deduction) and Schedule 1 (if you have income sources beyond wages, like self-employment or capital gains). Many filers need only the 1040 itself.

Key Takeaways

• The 1040 is the federal income tax form you file to report all income and calculate your tax or refund for the year.
• You must file if your income exceeds the threshold set by the IRS for your age and filing status, which changes each year.
• The 1040 asks for personal information, income from all sources, deductions, and credits you are may have access to to claim.
• Most people file the 1040 with tax software, through a tax preparer, or by mail; the IRS does not have a phone line to file directly.
• You file the 1040 by the tax important date, usually April 15, though you can request an extension to October 15.

Who has to file a 1040

You must file a 1040 if your income is above a certain threshold. That threshold depends on your age, filing status (single, married filing jointly, head of household, and so on), and whether you are claimed as a dependent on someone else's return. The IRS publishes the income thresholds each year in January or February, and they change based on inflation.

For example, if you are a single person under 65 and your income was above the threshold for your year, you file. If you are married filing jointly and both spouses are under 65, the household threshold is higher. If you are 65 or older, the threshold is lower because the IRS assumes you have less income at that age.

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 is how you get a refund. You should also file if you are may have access to to refundable credits like the Earned Income Tax Credit (EITC) or the Child Tax Credit, because filing is the only way to receive them.

What information goes on the 1040

The 1040 has several sections. The top asks for your name, address, Social Security number, and filing status. Below that is the income section, where you report wages from your W-2, interest and dividends, capital gains or losses, self-employment income, and any other money you received.

Next is the deductions section. You choose either the standard deduction (a flat amount set by the IRS each year based on your filing status) or itemized deductions (specific expenses you list, like mortgage interest or charitable donations). Most people take the standard deduction because it is simpler and often larger.

Then you calculate your taxable income by subtracting your deduction from your total income. You use the tax tables or tax software to find your tax based on that number. Finally, you subtract any tax credits you are may have access to to — such as the Child Tax Credit or education credits — and compare that to the taxes already withheld from your paychecks. The difference is either what you owe or what the IRS owes you.

The difference between the 1040 and other tax forms

The IRS offers a simpler form called the 1040-SR for people 65 and older. It has the same purpose as the 1040 but uses larger type and is organized slightly differently. If you are 65 or older, you can file either the 1040 or the 1040-SR; both are accepted.

Some people used to file the 1040-EZ or 1040-A, which were shorter forms for straightforward tax situations. The IRS discontinued those forms after 2017, so now almost everyone files the 1040 or 1040-SR. The 1040 is flexible enough to handle straightforward situations and complex ones.

You may also need to file additional schedules or forms depending on your situation. Schedule C is for self-employment income. Schedule D is for capital gains and losses. Schedule E is for rental income. These attach to your 1040 and provide the detail the IRS needs to verify your income.

How to file your 1040

You have three main routes: file using tax software, work with a tax preparer or CPA, or file by mail. Most people use tax software because it is fast and catches errors. The software walks you through questions about your income and life situation, fills in the 1040 for you, and can file it electronically to the IRS.

If you use a tax preparer, you bring your documents (W-2s, 1099s, receipts for deductions) to their office or send them digitally. The preparer fills out the 1040 and files it for you. If you file by mail, you print the 1040, sign it, and mail it to the IRS address for your state, which is listed in the form instructions.

Electronic filing is faster than mail and produces a confirmation from the IRS within 24 hours. If you are owed a refund, electronic filing also gets your money to you faster — usually within 21 days, though it can take longer if there are errors or if you claim certain credits.

When the 1040 is due and what happens if you miss the important date

The 1040 is due on April 15 of the year following the tax year. For example, your 2023 taxes are due April 15, 2024. If April 15 falls on a weekend or holiday, the important date moves to the next business day.

If you cannot file by April 15, you can request an automatic extension from the IRS. Filing Form 4868 gives you until October 15 to file your return. The extension gives you more time to file, but it does not give you more time to pay. If you owe taxes, you should pay by April 15 anyway to avoid penalties and interest, even if you have not filed yet.

If you file late without an extension, the IRS charges a failure-to-file penalty. If you owe taxes and do not pay by the important date, you face a failure-to-pay penalty plus interest on the unpaid amount. Both penalties are calculated as a percentage of the tax owed and grow each month the debt remains unpaid.

Common mistakes on the 1040

The most common mistake is mismatching income. If you report $50,000 in wages on your 1040 but your employer reported $55,000 on your W-2, the IRS will catch the difference and send you a notice. Always check that the income figures on your 1040 match the W-2s and 1099s you received.

Another frequent error is forgetting to sign and date the form. An unsigned 1040 is not valid, and the IRS will reject it. If you file electronically through software or a preparer, your signature is usually captured digitally, but if you mail a paper return, you must sign it by hand.

People also sometimes claim the wrong filing status or forget to report all their income sources. If you are married, you must decide whether to file jointly or separately — filing jointly almost always results in a lower tax. If you received a 1099 for freelance work or investment income, you must report it even if it was a small amount.

Frequently Asked Questions

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

Only if your income exceeds the IRS threshold for your age and filing status. However, even if you are below the threshold, you should file if you had taxes withheld from paychecks, because filing is how you get a refund. You should also file if you are may have access to to refundable credits like the EITC.

Can I file my 1040 on my phone?

Most tax software companies offer mobile apps that let you start your return on your phone, but you usually need to finish and sign it on a computer or through their website. Some software is fully mobile-friendly, so check the provider's website to see what works on your device.

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 amendment. If you are owed money because of the correction, you will receive a refund. If you owe more, you will receive a bill plus 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 (W-2s, 1099s, receipts) for at least three years. The IRS can audit returns up to three years back, and you need these documents to prove what you reported.

What is the difference between filing status and tax bracket?

Filing status is your legal relationship category — single, married filing jointly, head of household, and so on. Tax bracket is the percentage rate you pay on your income, which depends on your filing status and taxable income. Your filing status determines which tax table you use to find your bracket.