The IRS says you should keep tax returns and the paperwork supporting them for at least three years after you file the return — the amount of time the IRS has to audit you. So that’s how long we advise in our charts.
Check with your state about state income tax, though. Some make you keep tax records a really long time: In Ohio, it’s 10 years.
The IRS can also ask for records up to six years after a filing if they suspect someone failed to report 25% or more of his gross income. And the agency never closes the door on an audit if it suspects fraud. (HouseLogic)
Danette O'Neal, PhD 