This was posted in a newspaper article a while back
Tax documents: Save any of the paperwork needed to back up your income tax return for at least four years. The Internal Revenue Service can audit your return for three years after it has been filed — four years after you’ve earned the income.
Some experts say that’s long enough to save W-2 forms, proof of medical expenses, donations and other items for which you may be claiming deductions, and other such items. But other experts say it is wise to retain such records for up to seven years, since the IRS can revisit your filing if it believes there’s been fraud, or that income has been substantially underreported.
Personal papers: Marriage certificates, birth and death records, social security cards and other personal documentation should never be discarded, and should be kept in a safe place.
Investment records: Items like stock certificates can be turned over to a broker for safe keeping. Save brokerage statements, trade slips and similar documents until stock is sold, then follow same guidelines as tax papers to documents taxable gains, said Cindy Hockenberry, tax information analyst at the National Association of Tax Professionals.
Without backup documentation, the IRS will determine the original cost to be zero, greatly amplifying the gains on which tax must be paid. Permanently retain paperwork related to the status of pensions and retirement benefits.
Banking paperwork: Generally, there’s little need to hold on to statements or most canceled checks once they’ve been reconciled. Some experts advise holding on to these for up to a year, some for as little as three months. Save mortgage and loan documents until those loans are repaid.
Bills: Save credit card bills long enough to check for accuracy, ensure you’re credited for returns. Some experts advise retaining them for a year. It is also advisable to retain three months of utility bills, which are frequently required to establish place of residence in applying for a mortgage, library cards and the like.
Pay stubs: Some experts advise retaining these for a year, then discarding and retaining the final stub showing total annual income.
Receipts: Save those for major purchases until warranties expire. Save records of improvements to your home until it is sold, to document the size of the gain that may be taxable.