With hand-keyed transactions you run a greater risk of fraud because the magnetic strip information is not available. If you are in a retail environment you can do the following:

1. Check your terminal and make sure it is working properly. You can try to swipe your own card to ensure the issue is not with your equipment.
2. You can also check to see if the number embossed on the front of the card is the same as the number indented on the back. There are scams where thieves will shave the numbers to alter the embossed numbers on the front of a card.
3. Look at the expiration date and make sure it is valid.
4. It is important to get an imprint of the card and have the customer sign the imprint slip. This way you can confirm the signature matches the back of the card.

If you take cards over the internet, make sure you are following Payment Card Industry Data Security Standards. Seeking out proper fraud control software is a key element to keeping your transactions safe and keeping site secure.

Most people that are going to use fraudulent stolen cards follow the same patterns. Some key things to look out for are people making large purchases without any regard for size, color, or price. Some will try to distract you or rush the sale by asking questions about other items while they are at the register being rung up. Many will make a purchase then return to the store to make another purchase shortly after.

Visa and MasterCard both have security features in place on their cards that I believe all retail sales people should be trained on. For example, all Visa Cards have a Dove or Flag Hologram on the front, or a mini Dove on the back.  It is important to become familiar with the items (or lack thereof) that can easily signal an instance of fraud. 

The first involves using the Luhn algorithm (also called the "Mod 10 Method "), which was developed as a way to validate unique numbers such as credit card numbers and social security numbers.

To further validate credit cards, you’ll want to obtain authorization from the issuing bank for 1.) address verification (AVS) and 2.) cvv2 – the three or four digit code found on the back of credit cards. Banks will respond with match or mismatch codes for street address, zip (5 and or 9 digits) and cvv2.

But what else can you do? These methods are well known and criminals can find ways around them. A few simple precautions go a long way. Here are some tips for validating credit cards:

• Double check orders where the shipping address doesn’t match the billing address. Oftentimes these are legitimate but I still view it as a red flag, especially for international orders.
• Require customers to create accounts or profiles to place an order. You can even validate new customers’ credit cards before they make a purchase by placing a $1 authorization that will fall off the card in a few days (just make sure to inform your customers!). Keep in mind that there is not a standard amount of time for an authorization to remain on a debit or credit card. Issuing banks determine the exact duration but typically most stay valid for three to 10 days. If you’re concerned about it you can call the bank and ask them to void the transaction.
• Use a credit card payment gateway provider that offers multi-level credit card validation and fraud prevention services. Transaction grading, advanced transaction management reporting, BIN blocking and progressive identification tools can protect your business from fraudulent credit card activity and potential chargebacks.