If you're trying to stuff another year's worth of tax records into that bulging file cabinet or overflowing desk, it's time to figure out what you really need and what should be tossed.

The basic rule is to hold on to your tax return and whatever records you need to prove that it's accurate for at least three years. That's how long the IRS usually has to question your return.Keep whatever you would need - contracts, receipts, canceled checks - to convince an IRS agent auditing your return that the figures on it are accurate. If you don't get your canceled checks back, or if you pay by credit card or electronic transfer, the IRS will now accept bank or credit-card statements that show the date and amount of the payment and to whom it was made.

But if you underreported your income by more than 25 percent, the IRS has six years to call you on it, and if the IRS can prove you committed fraud, there's no statute of limitations.

Before you throw out old returns, check for information you may need in the future, such as:

- a return reporting the sale of one home and the purchase of another, and the Form 2119 on which you deferred tax on the gain. Keep these indefinitely.

- brokerage and mutual-fund statements. They'll be needed to establish tax basis when you sell the investment. Keep them as long as you own the investment and for three years after you sell.

- tax returns and Forms 8606 from years you made nondeductible IRA contributions and Forms 5498 showing how much you've withdrawn from IRAs. Keep these until three years after your IRAs are empty.