When you fail to file taxes you could be subjected to tax evasion penalties. Keep in mind you can still file your taxes for up to ten years back. After the ten years are up the statue of limitations runs out. Filing your taxes could also mean paying some late fees. These fees are known as FTF penalties, or FTP penalties. These occur when you do not meet the dead line to file taxes or miss the due date to pay taxes.
For more information to file taxes for past years please read this article http://ez-online-tax-filing.com//what-to-do-when-you-have-not-filed-taxes-for-many-years.html