If you meet the filing requirements, then you are required to file a tax return on or before the April 15 deadline. Failure to file your tax return before the due date means that you are not in compliance with Internal Revenue Service tax law and thus, you are leaving yourself open to enforcement action by the IRS.
As of the 2009 filing season, you are allowed to earn up $9,350 before filing a tax return if single, $12,000 if head of household, $18,700 if married filing joint, $3,650 if married filing separately or $15,050 if qualifying widow (er). If you did not earn above the amount required for your filing status, then you are not required to file last year.
Penalties And Interest
If you didn't file taxes and you owe money, then you will be charged penalties and interest on the unpaid tax. Penalties and interest are charged from the day the return was due--usually April 15t). The Failure to Pay penalty is ½ of 1 percent of the unpaid tax for each month the tax is late and the Failure to File penalty is 5 percent for each month the tax is late, but not more than 25 percent.
Statute of Limitations
You only have three years from the due date of the return to claim a refund. So, even if you're owed a refund, you should still find before the three-year statute elapses.