Take a good look at your credit card, what do you see? The name or logo of the issuing financial institution, your name (embossed on the card, thank you), the date when you first became a member (normally, they just indicate the year), when the card will expire, the card number ( of course!), the trademarks of either Visa or MasterCard (if your card does not have this, it's okay, your card is still valid – just not part of their network of banks), the magnetic strip (take care not to scratch that part), a small area where you affix your signature, and … what's that? An extra set of numbers at the back of your card? What are these for?
If you're wondering what those extra numbers represent and what their purpose is, then it's time you found out. Those three digits are your security numbers. In this day and age where face-less transactions are accepted, these numbers protect you from falling prey to unscrupulous individuals (who, for one reason or another, know your card number by heart). Without these numbers, any online, television, or telephone purchases will not be verified and these will not be charged to your account.
Security numbers are randomly generated and are added to cards, from the exclusive "do not leave home without it" American Express to the widely popular Visa and MasterCard brands. As previously stated, these numbers prevent thieves from using your credit card with merchants who are unable to personally check if the signatures on the card (and on the receipt) are alike. It is a security mechanism that has been developed primarily to reduce a growing number of internet frauds.
How do security numbers work? For non-personal transactions, particularly online purchases, the user is asked to plug in the last digits seen at the back of your card. Without the thief has your credit card, he will have to guess what these three numbers are. Once the digits are encoded, the system verifies this with the card issuer. The card issuer will then send an automated electronic response, to inform the merchant if (1) you have sufficient credit in your account for your intended purchase; and (2) if the information that was sent matches the data they have on file. Naturally, if the security numbers do not match, there is a large probability that that person makes the purchase is not the card holder.
If you often do internet purchases, it is best that you simply allocate one credit card for this purpose so you do not have to keep pulling out cards at every purchase. The less number of times your card is seen by other people, the less chances will there be for thieves to take note of your card number as well as the security digits at the back.
Be vigilant in protecting your identity. Do not divulge your pin number or lend your credit card to anyone. In addition, try to get credit cards where your photo is printed on the card face and sign your receipts (instead of just punching in a pin number). It is always better to be safe than sorry.