There is no simple answer to this question. While the basic rule is to keep records for three years after you have filed your tax returns, that period varies by type of information (e.g., employment records are key for at least four years, loans, depreciation schedules,property/real estate recoreds, etc.). Some records should be kept for six years, others need to be kept indefinetly. Documents that indicate ownership, such as automobile title and lien release or property deeds, need to be retained until the item or property is sold. Then keep a copy of the sales transaction. For credit or installment loans, you should keep copies of receipts, canceled checks, or other paperwork until the debt is paid or as needed.
In addition, if information is questioned by the Internal Revenue Service (IRS), the rentention period becomes three years after the final resolution of the items in question for records related to the item in question.
You should also consult your accountant or tax preparer for specific advice.
Always keep these items in a safe place such as a safety deposit box or in other fire- and flood-proof location.
For a more complete answer, go to the IRS Web site at http://www.irs.gov/businesses/small/article/0,,id=98513,00.html.