According to the IRS, you should keep your records 3 years, 6 years, 7 years or permanently. It all depends on the time limit you are allowed to amend your taxes, or the time limit that the IRS can come after you to assess additional taxes.
For instance, the IRS advises, if you filed a fraudulent return, or did not file a return at all, you should hang on to your tax filing and/or records indefinitely (this is actually what they say). There is no limit to the time the IRS can come after you.
If you don't report income you should have, and it's more than a quarter of your gross income, keep records for six years.
You may actually want to keep your tax records for longer than may be required for the IRS, for insurance, business or other reasons.
For a full recap, check the IRS site here http://www.irs.gov/businesses/small/article/0,,id=98513,00.html
This answer was edited by TWinston 422 days ago.
Reason: Small addition





