In case of a failure to file a tax return, the tax may be assessed or a proceeding in a court for the collection of owed tax may begin at any time even without assessment.
A un-filed Tax Return (when you owe taxes) does not have STATUTE of LIMITATIONS. The general rule is that the IRS must assess a tax within a THREE-YEAR after a tax return is filed. But if you failed to file a tax return, the IRS has right to examine the tax year any time within your lifetime.
You can eliminate any possibility of being prosecuted for tax fraud when you voluntarily file all un-filed tax returns.
Any individual taxpayer who fails to pay estimated tax and fails to file a tax return, the taxpayer may be charged with a misdemeanor, be subject to a jail term of not more than ONE year and subject to a fine of $25,000 ($100,000 for a corporation).
There is no penalty for failure to file a tax return if a refund is due. In order to receive a refund, the return must be filed within THREE-YEARS of the due filing date. The deadline date for claiming any refund due is THREE-YEARS after the return was filed, OR TWO-YEARS after the tax was paid, whichever is later.
If a taxpayer willfully does not file a tax return and willfully fails to pay the tax liability, the taxpayer may be charged with a felony and subject to a jail term of up to FIVE years.
If you are self-employed, you must file your tax return and report self-employment income within THREE years of the due date in order to receive your Social Security credits toward your retirement.