There are three sections of the Internal Revenue Code that are of special significance for taxpayers who are late in filing the tax return, late in paying the tax return or who are concerned about an audit.
Section 6511 of the IRC
The 3 year refund statute. This statute allows the IRS to keep your tax refund if you file a tax return more than 3 years after it's due date. A moneymaker for them I am sure.
Section 6502 of the IRC
The 10 year debt collection statute. This statute says that after 10 years have passed (with some exceptions) from the date the debt was “assessed” the debt is no longer valid. i.e. gone…poof…etc. This also means that the underlying lien is gone as well.
Section 6501 of the IRC
This is the 3 year audit statute. The correct tax return enjoys the protection of this statute. i.e. the IRS cannot audit the return if more than 3 years have passed since filing.
To read more about these statutes theInternal Revenue Manual 25.6.1, is a good place to start.