There are several sets of numbers on both debit or credit cards, which share the same characteristics. Each set of numbers has a specific purpose, such as to identify your account number, the identity of the card issuer and to prevent others who access your account number from making unauthorized purchases. All the numbers shown on your debit or credit card should be shared sparingly. If these numbers fall into the wrong hands your checking account could be in jeopardy, as well as your personal information and credit history. An understanding of where the numbers are and what they mean could help keep you safe.
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.
Keep your debit and credit cards safe by not sharing your card number with anyone but an authorized merchant. Card numbers can be stolen and used easily. Protect yourself.
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.
Beware of scams asking for the security code number. There are documented cases of callers pretending to be card security representatives. The call may seem legitimate, but always contact your card issuer before giving out any sensitive information.