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

The Form 1040 is the federal income tax return form. You file it with the Internal Revenue Service (IRS) to report the money you earned during the tax year, the taxes already taken from your paychecks, and to calculate whether you owe more tax or will receive a refund. Almost every person who earns income in the United States files a 1040 or a variation of it.

The form itself is one page, but it connects to other documents called schedules and worksheets that you attach depending on your situation. For example, if you have investment income, you attach Schedule B. If you own a business, you attach Schedule C. The 1040 is where all those pieces come together.

You file your 1040 once per year, typically between January 1 and April 15 of the following year. The IRS uses your 1040 to verify that you paid the right amount of tax. If you paid too much through withholding or estimated tax payments, you get a refund. If you paid too little, you owe the difference.

Key Takeaways

  • The 1040 is the main federal income tax form that reports your total income, deductions, and tax liability for the year.
  • You attach schedules to your 1040 depending on your income sources — such as Schedule C for self-employment income or Schedule D for capital gains.
  • The form shows the IRS how much tax was already withheld from your paychecks and whether you owe more or will receive a refund.
  • Filing a 1040 is required if your income exceeds the threshold set by the IRS for your filing status, which changes each year.
  • You can file your 1040 by mail, through tax software, or with the help of a tax professional.

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 also asks whether you are a U.S. citizen and whether anyone can claim you as a dependent.

The main body of the form lists different types of income. You report wages from a job (taken from your W-2 form), interest and dividends from savings and investments, self-employment income, capital gains or losses from selling stocks or property, and other income sources. Each type of income has its own line.

Below the income section, you either claim the standard deduction or itemize deductions. The standard deduction is a flat amount that reduces your taxable income; it varies by filing status and age. Itemizing means you list specific expenses like mortgage interest, property taxes, or charitable donations instead.

At the bottom of the form, you enter the total tax you owe based on your income and deductions, subtract any tax already withheld from your paychecks (shown on your W-2 or 1099 forms), and calculate your refund or amount owed.

The difference between the 1040 and its variations

The IRS offers two shorter versions: the 1040-SR (for people age 65 and older) and the 1040-NR (for nonresidents). Most people file the standard 1040.

The 1040-SR has larger print and is organized slightly differently to make it easier to read, but it asks for the same information. You can use it if you are 65 or older on December 31 of the tax year.

The 1040-NR is for people who are not U.S. citizens and do not have a green card. It has different rules about which income counts as taxable and which deductions you can claim. If you are a resident alien (someone with a green card), you typically file the standard 1040 instead.

All three versions connect to the same schedules. Whether you file a 1040, 1040-SR, or 1040-NR, you still attach Schedule C if you have self-employment income, Schedule A if you itemize deductions, and so on.

Schedules and worksheets you attach to your 1040

The schedules are separate forms that provide detail about specific types of income or deductions. You only file the schedules that explore to you.

Schedule A is for itemized deductions. You file it if you want to deduct specific expenses instead of taking the standard deduction. Common itemized deductions include mortgage interest, state and local taxes (capped at $10,000), charitable donations, and medical expenses above a certain threshold.

Schedule B reports interest and dividend income. If you earned more than $1,500 in interest or dividends during the year, you must file Schedule B and list each source.

Schedule C is for self-employment income. If you own a business, are a freelancer, or have other self-employment income, you file Schedule C to report your business income and expenses, then calculate your net profit or loss.

Schedule D reports capital gains and losses from selling stocks, bonds, real estate, or other investments. If you sold any investments during the year, you report the sale price, what you paid for it, and your gain or loss on Schedule D.

Other schedules exist for rental income (Schedule E), farm income (Schedule F), and other specific situations. The IRS instructions for the 1040 tell you which schedules you need based on your income sources.

When you must file a 1040

You must file a 1040 if your income exceeds a threshold set by the IRS. The threshold depends on your filing status, age, and type of income. For example, in 2023, a single person under 65 had to file if their income was $13,850 or more. A married couple filing jointly had to file if their combined income was $27,700 or more. These thresholds change each year.

Even if your income is below the threshold, you should file if you had taxes withheld from your paychecks or made estimated tax payments. Filing allows you to claim a refund of the tax you overpaid.

You must also file if you are self-employed and your net self-employment income is $400 or more, regardless of your total income. Self-employment tax funds Social Security and Medicare, and the IRS requires you to report it.

If you received certain tax credits during the year — such as the Earned Income Tax Credit or the Child Tax Credit — you may need to file to claim them, even if your income is below the filing threshold.

How to file your 1040

You have three main options: file by mail, use tax software, or work with a tax professional.

Filing by mail means printing the form, filling it out by hand, and mailing it to the IRS address listed in the instructions. The IRS processes paper returns more slowly than electronic ones, and errors are more likely to delay your refund.

Tax software guides you through the form question by question and calculates your numbers automatically. Many software providers offer free versions if your income is below a certain level. The software checks for common errors before you submit and files electronically, which is faster.

A tax professional — such as a certified public accountant (CPA) or enrolled agent — can prepare your return for you. They charge a fee, but they handle the entire process and may find deductions you missed. They also file electronically on your behalf.

Regardless of which method you choose, you need the same documents: your W-2 forms from employers, 1099 forms for other income, receipts for deductions if you itemize, and records of any tax payments you made during the year.

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. The IRS sets an income threshold each year — if you earned less, you are not required to file. However, if your employer withheld taxes from your paychecks, you should file to get a refund. You can find the current threshold in the 1040 instructions on the IRS website.

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

A W-2 is a form your employer sends you showing how much you earned and how much tax was withheld. A 1040 is the form you file with the IRS that reports all your income from all sources and calculates your total tax. You use the information from your W-2 to fill out your 1040.

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

If you are a resident alien (someone with a green card or valid visa), you file the standard 1040. If you are a nonresident alien, you file Form 1040-NR instead. The rules about which income is taxable differ for nonresidents. You can find more information in the 1040-NR instructions.

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 expecting a refund, there is no penalty, but you lose the refund if you wait too long — the IRS typically holds refunds for three years. If you cannot file by the important date, you can request an extension, which gives you until October 15 to file.

Do I need to attach my W-2 to my 1040 when I mail it?

No. The IRS receives a copy of your W-2 directly from your employer. If you file electronically, you do not send your W-2 at all. If you file by mail, keep your W-2 for your records but do not mail it with your return. However, if the IRS later questions your return, you may need to provide it.