You must file a 1040 if your income exceeds the IRS threshold for your filing status, or if you owe taxes, received certain credits, or had taxes withheld from your paychecks
The IRS requires you to file a 1040 when your gross income — the total you earned before deductions — crosses a threshold that depends on your age, filing status, and type of income. Even if you earned less than the threshold, you should file if you had taxes withheld from your paychecks, because filing is how you get a refund. The threshold amounts change each year, so you need to check the current year's rules, not last year's.
Filing is also required if you owe self-employment tax (you worked for yourself), received certain tax credits like the Earned Income Tax Credit, or had a spouse file separately while you filed jointly the year before. The rule is not "file if you think you owe" — it is "file if the IRS says you must," and that rule depends on numbers, not guesses.
Key Takeaways
- The income threshold that triggers a filing requirement changes every year and depends on whether you are single, married, over 65, or claimed as a dependent.
- You must file even if you earned below the threshold if you had income taxes withheld from paychecks, because that is how you recover the money.
- Self-employed people must file if they earned $400 or more in net profit, regardless of other income.
- Filing is required if you received certain tax credits, had a dependent, or are claimed as a dependent on someone else's return.
- The IRS publishes the current year's thresholds on its website and in the 1040 instructions each January.
Income thresholds by filing status and age
The IRS sets a standard deduction — an amount you can earn without owing federal income tax. If your gross income is below this amount, you do not have to file. If it is above, you do. The standard deduction varies by filing status (single, married filing jointly, head of household, married filing separately, or may have access to widow/widower) and by age.
For example, a single person under 65 has one threshold; a single person 65 or older has a higher one, because the IRS assumes older workers have lower income. A married couple filing jointly has a higher threshold than a single person, and a married person filing separately has a lower one. These numbers shift upward each year to account for inflation.
To find your threshold, look up the current year's 1040 instructions on the IRS website (irs.gov), or ask a tax preparer. Do not use last year's numbers. The instructions include a table that matches your filing status and age to the threshold amount.
When you must file even if you earned less than the threshold
You must file a 1040 if you earned less than the standard deduction but had federal income tax withheld from your paychecks. Withholding is the money your employer sent to the IRS on your behalf. If you earned $10,000 but the threshold is $13,850, you do not owe tax — but if your employer withheld $800, filing is how you get that $800 back.
You must also file if you earned income that was not subject to withholding — for instance, interest from a savings account, or a 1099 from a side job — and your total income (including that unwithheld income) exceeds the threshold. The IRS needs to know about all income, not just the income your employer reported.
Filing is also required if you are claimed as a dependent on someone else's return (usually a parent's) and you had unearned income above a certain amount, or earned income above a lower threshold. A dependent's filing requirement is stricter than an independent person's, because the IRS wants to prevent parents from hiding a child's income.
Self-employment income and the $400 rule
If you worked for yourself — as a freelancer, contractor, or small business owner — you must file a 1040 if your net self-employment income (what you earned minus business expenses) was $400 or more. This rule applies even if you had no other income and even if $400 is below the standard deduction for your filing status.
Self-employment income triggers the requirement because you owe self-employment tax, which funds Social Security and Medicare. The IRS collects this through the 1040, not through employer withholding, so filing is mandatory. You report self-employment income on Schedule C (Profit or Loss from Business) and attach it to your 1040.
Tax credits and other reasons to file
You must file if you are may have access to to certain tax credits, even if you owe no tax. The most common is the Earned Income Tax Credit (EITC), which is a refundable credit for low- to moderate-income workers. If you earned $20,000 but the EITC would give you a $3,000 refund, you must file to claim it — the IRS will not send it to you automatically.
Other credits that require filing include the Child Tax Credit, the American Opportunity Credit (for education), and the Child and Dependent Care Credit. These are valuable — sometimes worth thousands of dollars — and filing is the only way to receive them. If you think you might may have access to for any credit, check the 1040 instructions or speak with a tax preparer.
What happens if you do not file when you must
If you owe taxes and do not file, the IRS will charge you a failure-to-file penalty, which is usually 5% of the unpaid tax per month, up to 25%. You will also owe interest on the unpaid amount. These penalties compound, so the longer you wait, the more you owe.
If you are owed a refund and do not file, you straightforward do not get the money. The IRS does not send refunds without a return. However, you can file a return up to three years after the original due date and still claim the refund — after three years, the money goes to the U.S. Treasury.
If you are unsure whether you must file, filing is the safer choice. Filing when you do not have to does not hurt you; not filing when you must can cost you money and create complications with the IRS.
How to find the current year's filing requirement
The IRS publishes the current year's income thresholds in the 1040 instructions, which are free on irs.gov. Search for "1040 instructions" and the current year. The instructions include a worksheet that asks your filing status and age and tells you the threshold amount.
You can also call the IRS at 1-800-829-1040 (Monday through Friday, 7 a.m. to 7 p.m. your local time) and ask whether you must file. Have your filing status, age, and total income ready. A tax preparer or your local library's tax information program can also help you determine whether filing is required.
Frequently Asked Questions
Do I have to file if I am a dependent and earned less than the threshold?
It depends on the type of income. If you earned only wages (W-2 income), the threshold is lower than for an independent person — usually around $13,850 for 2023, but check the current year's instructions. If you had self-employment income of $400 or more, or unearned income (interest, dividends) above a certain amount, you must file even if your total income is low.
What if I had taxes withheld but earned below the threshold?
You should file. Withholding means the IRS is holding your money. Filing a 1040 is how you tell the IRS to return it. You will likely get a refund, and filing takes the same time whether you owe or are owed money.
Do I have to file if I am married and my spouse does not work?
If you file jointly, your income threshold is based on the married filing jointly standard deduction, which is higher than the single threshold. If you file separately, each of you has a lower threshold. Check the 1040 instructions for the current year's amounts for your filing status.
What if I earned money from a side job but had no taxes withheld?
You must report that income on your 1040. If the total (including any W-2 income) exceeds the threshold for your filing status, you must file. Even if it does not, you may owe self-employment tax if the side job income was $400 or more, which also requires filing.
Can I file early, before the important date?
Yes. The IRS begins accepting returns in late January each year. Filing early means you get a refund sooner if you are owed one. There is no penalty for filing before the April important date.