When I was a kid, my friend Becky had a stack of photocopied coupons for free Whoppers at Burger King.

It was like a gold mine. Every day after school, we parked our butts in a booth and feasted. It was awesome.

It turns out the coupons were fake. We didn’t know it. The restaurant didn’t know it. But eventually we all found out. We didn’t get into trouble, but we did get a bunch of free burgers. Everybody wins, right?

Wrong.

Thanks to the Internet, counterfeit coupons are everywhere. And because retailers have been getting burned to the tune of millions of dollars each year, they’re starting to crack down.

Many stores have put a limit on the number or dollar value of printed coupons they’ll accept. Some have stopped accepting Internet and printable coupons altogether.

And that stinks for those of us who have legitimate ones.

Too, it’s embarrassing to get to the register and have the cashier cast doubt on your coupon—acting like you’re stealing or something. So it’s helpful to make sure you have the goods and can coupon with confidence.

Here are some helpful hints to steer clear of fake coupons, from www.couponsherpa.com,

a Web site that hunts down promotional codes and printable coupons:

Check the bar code. It should have 12 digits and not be smudged.

Watch for fine print. All coupons have mouseprint, which includes separate instructions for the retailer and the consumer as to how to redeem the coupon.

Make sure it has an expiration date. Only in my fantasy world do coupons never expire.

Online coupons should play a little hard to get. Most legit coupon providers on the net make you go through a registration process or require you to sign up for a subscription of some sort.

If it’s too good to be true, it probably is. If you get a pop-up promising a coupon for a free iPod simply for answering a few survey questions, I hope you’ll know better than to fall for it.

And while coupons for free products and screaming deals are out there, it’s best to check with the retailer or manufacturer with which the coupon originated to be sure it’s not a fake.

Watch out for coupons that have been clipped from newspapers, then scanned and uploaded to a Web site as a printable coupon. Scanning or photocopying coupons is illegal. To check whether a printable coupon is for real, check with its original manufacturer or retail source.

It’s illegal to buy or sell coupons. Beware of sites asking for upfront fees.

Coupons clipped from newspapers, magazines and inserts will have printing on both sides. A blank back should be the tip-off to a rip-off.

If you find yourself the victim of a coupon scam or just want to learn more, you can contact the Coupon Information Center by visiting www.Cents-Off.com.