In a face-to-face card payment environment a well trained staff at the checkout can identify certain suspicious indications in a cardholder's behavior that can help prevent a potential fraudulent transaction from being processed. It is advisable that you do provide your personnel with proper training so that they know what signs to look for, in addition to following all other procedures for identifying fraudulent activity, such as identifying cards that have been tampered with, signatures on the sales receipts that do not much those on the back of the cards, etc. Keep in mind that identifying fraud before it actually takes place helps to avoid chargebacks against which you have no remedy. Here is a list of suspicious signs at the point of sale that you should look out for:

• Purchasing large quantities without much attention to details. If a customer is purchasing a sizable amount of merchandise, without much care for its size, color, or even price, that might be an indication for fraud.
• Ignoring free delivery. If your customer asks no questions or completely ignores a free delivery option, in favor of a quicker but paid one, this could be a warning sign.
• Attempting to rush the cashier into a quicker processing of the payment. Although your customer may really be in a hurry, such behavior can be intended to force the point-of-sale person to circumvent fraud prevention measures.
• Making multiple purchases within a short amount of time. If a customer completes a purchase, leaves the store and then comes right back in, he or she might be doing it because they believe that making multiple fraudulent transactions, each for a lesser amount, would not attract much scrutiny.
• Shopping either right after the store opens or before it closes. A fraudster might be shopping early in the morning or late in the evening, in the hope that the point-of-sale personnel will not be as attentive as during other stretches of the day.

You should keep in mind that, although suspicious, a certain behavior might be perfectly justified and explained in another, completely legitimate way. By themselves, none of the above examples constitutes a proof of a fraudulent activity. You should always use your observations of customer behavior in the context of the particular setting. Different establishments attract different types of customers and what is considered a normal customer behavior at one place might be interpreted as completely irregular at another.

Once you have accumulated enough observations to suggest that a fraudulent activity is probably taking place, you should contact your merchant bank's authorization center and make a "Code 10" request. You should keep the card in your possession, but only if it is safe to do so. If you feel threatened or uncomfortable, complete the transaction and make the call to your merchant account bank's center right after the customer leaves. Then follow the instructions your merchant bank gives you.