Requirements

• Mark your calendar.calendar for 2007 (april) image by Sergey Galushko from Fotolia.com
  
  The deadline for filing your tax return and paying your tax is April 15 or the following business day if April 15 falls on a weekend or business holiday; however, the Internal Revenue Service (IRS) will grant an automatic two-month extension if you request it, which can be expanded to six months under the right circumstances. Regardless of your extension request, you must still pay an estimated tax owed by April 15 or make other arrangements with the IRS.
  
  

Financial Implications

• Depending on your income, you may not have to file a tax return.tax forms image by Chad McDermott from Fotolia.com
  
  The penalties for not filing a tax return can be severe. For tax returns filed after 2008, the minimum penalty is $135 or 100 percent of the unpaid tax, whichever is smaller, and a fine of up to $25,000. This means that if your unpaid tax was $140 and you failed to file your tax return, you will be required to pay up to $25,275 ($140 in unpaid tax, $135 in penalty and $25,000 in fines), and that's just for the one year you missed. If you failed to file for multiple years, the potential penalties increases.
  
  

Other Penalties

• Don't file, and you might go to jail.behind the bars image by Yurok Aleksandrovich from Fotolia.com
  
  In addition to the financial implications, you may also incur criminal penalties as a result of your failure to file. According to U.S. Code Title 26 Section 7203, if you are convicted of misdemeanor tax evasion, you can be sentenced to up to one year in jail for every year that you failed to file a return. You will also be responsible for any court costs resulting from your conviction.
  
  

Statute of Limitations

• From a civil perspective, there is no statute of limitations on failure to file your tax returns. This means you will be liable for any unpaid taxes and penalties for as long as the taxes are due. However, there is a six-year statute of limitations on the criminal offense.
  
  

Requirements

• In some cases you may not actually need to file a tax return. For 2009, if you were single and under 65 years old as of December 31 and you made less than $9,350, you do not need to file a tax return. Or if you were married, both spouses were under 65 and your gross income for the year was less than $18,700, you also don't need to file a tax return. However, you may need to file one to get a reimbursement.