Industry professionals, consumer advocates and veteran shoppers have these tips for improving your odds of collecting on rebate claims:

• Before you leave the store, make sure the UPC code is still on the box. At stores that sell returned merchandise, the UPC code may already have been used for a rebate, making your request ineligible.
• Test the product to make sure it works before sending in the rebate.
• Read the rules carefully. Some require you to circle the product on the receipt. Others have strict deadlines. Make sure you’ve included the right mailing address. “Follow instructions to a T,” said Linda Badger, a staff attorney for the Federal Trade Commission. “Sometimes they ask for the original UPC code. Other times, the serial number.”
• Make sure you get enough receipts when buying multiple products. Consumer Paul Houle of Costa Mesa, Calif., who says he has collected $2,245 on 114 rebates in the past 18 months, said, “If you purchase more than one rebate product, and the store doesn’t print enough copies, you’re in trouble. … I’ve learned to carefully read online rebates before I buy.”
• Write legibly. David McIntyre, president of Global Fulfillment Systems, suggests using a mailing label, but that’s not always allowed. Some rebate claims must be handwritten.
• Keep copies of everything, especially the rebate form, so you know whom to contact if your rebate is lost or rejected.
• If you run into a problem with your claim, don’t call to yell at the person on the other end of the phone. “If someone cusses out the CEO, they’re not going to get the rebate,” said Bradley Morse, vice president of marketing at D-Link Systems Inc. “Cool heads prevail.”
• If your request is rejected, complain. Ask for the manager. Write to the CEO. Send copies of your complaints to government agencies.