To the long and lengthening list of scams and petty shakedowns, add a new one: Return fraud — when criminals take advantage of companies' return policies to get cash for stolen goods or return used items. The National Retail Federation says merchants can expect to lose $3.5 billion from return fraud this holiday season.

Retailers are fighting back by adopting increasingly stringent return policies. Result: You and your loved ones may have a much harder time returning or exchanging gifts after the holidays. The best way to protect yourself is to know the return policies before you buy.

Some tips:

Always check the return policy, which is often posted by the customer service counter or on your receipt itself. Stores are not obligated to accept returns, but they must comply with their stated return policies. Buying in advance may save you from the last-minute shopping frenzy, but it may also limit the time your friends and family have for returns.

To be safe, check the store's returns and exchange period. Ask for a gift receipt. The National Retail Federation advises stapling it to the merchandise tag so your gift recipients will have everything they need when making a return. Keep your original receipts, as well.

Find out a store's restocking fees, which are sometimes not clearly disclosed. A restocking fee, which can range from 5 percent to 25 percent of an item's cost, is charged when an item has been opened or removed from its original packaging. Restocking fees often apply to electronics purchases such as digital cameras and computers. Don't assume that a retailer's Web site has the same return policy as its brick-and-mortar counterpart. Retail Web sites often list their return policies under their "Terms and Conditions" sections.

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