We recommend to keep a copy of your tax return for a minimum of five years. Optimally, you should keep them indefinitely. Below is a table of the period of limitations for a tax return to be amended or audited:
|If you...||The period is...|
|Do not report income that is more than 25% of the gross income shown on your tax return.||6 years.|
|File a fraudulent return.||No limit.|
|Do not file a return.||No limit.|
|Owe additional tax and the above situations do not apply to you.||3 years.|
|Amend a return to claim a credit or refund.||2-3 years after the taxes were paid.|
|File a claim for a loss from worthless securities.||7 years.|
For tax returns involving property — rental property, depreciation, etc. — keep your records until they are no longer needed to compute gains or losses on the property or its replacements.
As for non-tax purposes, check with your insurance company or creditors. They sometimes require much older records than the IRS would.