On a Visa, Switch, MasterCard ,etc, please turn your card over and look in the signature strip. You will find (either the entire 16-digit string of your card number, OR just the last 4 digits), followed by a space, followed by a 3-digit number. That 3-digit number is your CVV2 number. (See below)
CVV2 is a security measure we require for all transactions. Since a CVV2 number is listed on your credit card, but is not stored anywhere, the only way to know the correct CVV2 number for your credit card is to physically have possession of the card itself. All cards made in Europe in the past 5 years or so have a CVV2 number.
Card Security Code
this number is printed on your card in the signature area of the back of the card. (it is the last 3 digits AFTER the credit card number in the signature area of the card). IF YOU CANNOT READ YOUR CVV2 NUMBER, YOU WILL HAVE TO CONTACT THE CARD ISSUER.