McClatchy Newspapers

If you are not checking your grocery receipts on a regular basis, you could be giving your local retailer extra cash. The culprit is technology.

At many checkouts, there are two scanners near the register. Sometimes an item can accidentally be scanned twice.

One way to avoid this is to listen. If you hear two beeps for one item, you are probably being charged twice.

Obviously, there is a similar problem with sales items that don't ring up at the advertised sales price.

If you find that you have been overcharged, most stores are willing to correct the problem.

Two grocers, Food Lion and Harris Teeter, will even give you the item or a similar product for free.

"Harris Teeter has a scan guarantee in place," said Jo Sorenson, spokeswoman for Harris Teeter. "If an item scans higher than the shelf tag or sign, customers will receive one like item free."

Karen Peterson, spokeswoman for Food Lion, said customers just need to bring the receipt in on their next visit.

Both stores say there is no time limit on when customers are allowed to get credit for incorrect scan. So whether you shop every two weeks or once a month, just keep the receipt until your next visit.

The only exception is alcohol and tobacco. You won't get those items replaced for free, but the stores will correct the overcharge.