The need to file
You must file a tax return if you have gross income above the limit for your filing status.
For tax year 2016, a single person under age 65 must file if he or she had gross income of $10,350 or more. A married couple filing jointly, both under age 65, must file if they had gross income of $20,700 or more.
Also, if income tax was withheld from your pay or other income, filing a return is always good idea even if it’s not required. This will allow you to get any refund the IRS owes you.
On the flip side, if you meet these requirements and choose not to file, you risk being on the hook for penalties and interest on any taxes owed.