Most convenience store retailers are unfortunately familiar with the term skimming.

Skimming is a process by which a thief places a device on a card reader — usually at the gas pump or ATM — and intercepts the magnetic stripe information from credit cards as unsuspecting customers slide their cards. This allows the thief to copy a customer’s credit card number and information and sell it or use it to purchase goods. Blank cards with magnetic stripes — like hotel key cards or gift cards — can be used to create a credit card with the stolen information.

Enter chip cards.

As more convenience stores upgrade their gas terminals to accept chip cards and become EMV (Europay Mastercard Visa) compliant ahead of the October 2020 deadline, fewer gas pumps are requiring customers to swipe their cards.

As a result, thieves have had to get more creative. That’s where shimming comes in. Shimming — something of an update on skimming — is a process where fraudsters insert a “shim” into the card reader that allows them to copy the chip-card information. Now, they can’t use that information to create another chip card. But they can use it to make a magnetic stripe card to be used online or at c-store retailers that have not yet upgraded to be EMV compliant.

C-stores can take a number of steps to protect their forecourts from would-be skimmers and shimmers. Just the presence of security cameras can be one deterrent against would-be thieves. Operators should also have a store employee check the pumps each shift. Placing security seals at pump access points can make it obvious if tampering has occurred. Post signs to let customers know not to use the card reader — and to alert management — if a seal appears to be broken.