The facility to shop remotely, over the internet or by phone, is becoming evermore popular and with this comes new and devious ways that criminals can steal from you. They devise all sorts of scams to try and obtain you credit or debit card details so that they can use them without your knowledge and in relative safety from being caught. It is incumbent on us and the card providers to find ways to prevent these criminals succeeding.
One of the recent innovations to help combat credit and debit card fraud is the introduction of a card security code, or CSC. This code is made up of a three or four digit number which is separate from the main card number. Often this is printed on the back of the card so that if someone has an impression of the card, they do not also have access to this code. This code should not be confused with your PIN which does not appear printed on the card at all.
The CSC operates in much the same way as a password. If you imagine your main card number is a username like you may have on a computer, then the CSC is the password that validates the transaction. It is most commonly used when you are shopping remotely. You will be asked for your card number in the usual way and then in addition you will be asked to enter separately your CSC. If the CSC is not the valid code for the card number you supply, the transaction will not proceed.