You're allowed to file a tax return for the year no matter how little time you worked or how little money you made. The Internal Revenue Service sets thresholds for income after which you must file, but doesn't have a minimum filing amount. For example, in 2013, if you're single and not claimed as a dependent, you must file if your total income exceeds $10,000. If your parents claim you as a dependent, you must file if you have earned income of more than $6,100.

Reasons to File

Even if you don't owe any taxes, you might want to file a return to get money back. For example, if you worked a summer job, you might have had money withheld for taxes that you ended up not owing. To get it back, you must file a return. Similarly, if you qualify for a refundable tax credit like the American opportunity credit for college costs, the only way to claim that money is by filing a return.