Conducting payment card transactions through a payment network through a card reader with a merchant authentication code attached. A payment is processed in connection with a transaction using a payment card. Prior to approving the transaction, the payment card holder is contacted and requested to provide the merchant authentication code. If the merchant authentication code provided by the payment card holder is consistent with the merchant authentication code affixed to the device, approving the transaction. The merchant authentication code may be text, a bar code, a quick response code, a hologram or other code. The merchant authentication code may include information regarding the merchant such as location, business name and the like.