The Card Face
Look at the string of digits on the face of your debit card. Visa and MasterCard, the most common issuers of debit and credit cards, have 16 digits. These digits represent the card issuer and your specific account number.
Look at the first two digits. For both Visa and Mastecard the first digit identifies the card issuer; "4" is Visa and "5" is MasterCard.
The remainder of the digits are to identify which specific bank issued the card, as well as your specific account number and account type. The account type is defined by the card issuer.
The Flip Side
Take a look at the flip side of your debit or
credit card. There is one very important number you need to know about. The CVV2 number, or security code number, is located on the back of most cards.
Give this number only to an authorized retail merchant. This three-digit number is used by merchants as a way to verify that the cardholder is present at the purchase. If a card number is stolen, it is less likely that the thief would have this information, thus it is a way to protect both you and the merchant from fraudulent purchases.
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