Generally, you must keep your records that support an item of income or deductions on a tax return until the period of limitations for that return runs out.
The time you are required to keep records includes the period of time during which you can amend your tax return to claim a credit or refund, or that the IRS can assess more tax. The following situations contain the periods of limitations that apply to income tax returns. Unless otherwise stated, the years refer to the period after the return was filed. Returns filed before the due date are treated as filed on the due date.
Are the records connected to assets?
Keep records relating to property until the period of limitations expires for the year in which you dispose of the property in a taxable disposition. You must keep these records to figure any depreciation, amortization, or depletion deduction and to figure the gain or loss when you sell or otherwise dispose of the property.
Example: You write a $4,000 check for hardwood flooring in a rental house in 2003. In 2011 you sell the rental property. The IRS may audit your 2011 return in 2012, 2013 or 2014, and you may need to prove that expenditure, because the flooring was set up on depreciation over 27 1/2 years and had some remaining un-depreciated basis at the time you sold the property.