If you are a regular user of online purchases, you will have noticed that a code called CVV or CVC is requested to validate the operation. The Card Verification Value (CVV) or verification/validation value code is a 3 or 4-digit number that is located on the back of credit and debit cards, at the end of the box located for the signature of the cardholder.

Security code: another method to validate the payment:

In addition to asking for the CVV code when you make a purchase online, currently, the vast majority of banks have implemented another method of payment verification - the security code.

If you are a regular at online purchases, surely you have already received it in one of your payments. When you confirm the payment on the platform, and after including the CVV, the bank sends you an SMS with several digits that you must enter to complete the process. 

What do the credit or debit card numbers mean?

The credit or debit card numbers that appear on the front grouped four by four have a meaning. In them, we will identify the type of card, the issuer, the country that issues it, and a check digit. This code on the front of the cards is adapted to ISO which indicates the positions and meanings of all these numbers. We will break down the code below:

The first digit indicates what type of entity is the card issuer. As you can see in the following table, the cards of bank entities that we have will have as the first of the numbers 4 or 5. 

This first number of the credit or debit card not only details what type of entity is the issuer but also which is the payment company behind it. So, if it starts with 4 it will be VISA and if it starts with 5 it will be Mastercard, while if it starts with number 3 it will probably be American Express.

If we look at the back of the card, we see that we have 2 groups of numbers, separated by a space. Generally, the first group is called CVV1, which corresponds to the last 4 numbers of the 16-digit code on the front of the card. 

The second part is CVV2 which is a random number algorithm. Although both groups of numbers are technically CVV or CVC. When they ask us to enter the CVV or CVC of our credit or debit card, we must write the second group of numbers, that is, the group consists of 3 digits, located usually in the right margin of the signature box.