Whether you’re required to file a tax return will depend on several factors, including your gross income, filing status, age, and whether you’re a dependent on someone else’s federal income tax return. And you may have to file even if you don’t owe any tax.

To get more specific information on who must file, check out IRS Publication 501. For most people, gross income is the main trigger for filing requirements. For example, in 2020, the filing threshold for single people younger than 65 was $12,400. For married couples filing jointly, it was $24,800 if both spouses were younger than 65.

If you were named as a dependent on someone else’s return and had income, you might also have to file, even if your income was much lower than the general threshold. Publication 501 has more detailed information on when dependents must file.

You’ll also need to file a return if you had at least $400 in self-employment earnings or meet other specific requirements, such as earning untaxed tips, receiving money from tax-exempt churches, or owing alternative minimum tax. IRS Publication 501 goes into details about these and other special situations.