运通卡（American Express）的安全码叫做 CID （Card Identification Number），有4位数字，平印在信用卡正面信用卡卡号上方。 银联卡（China Pay）的安全码叫做 CVN2 （Card Validation Number 2），有3位数字，平印在信用卡背面签名栏上卡号后4位处之后。

2020年11月19日 · This three- or four-digit code tells the merchant that you are in possession of the card. The code also protects you from credit card fraud. Because you’re not in front of them during a transaction online or over-the-phone, the merchant can’t verify your identity with photo ID or by matching your signature to the one on the back of the card.

2024年10月14日 · CVV numbers are the extra three or four digits on a credit card. Known by many names, they are an important element of credit card security. By using data that businesses can’t store to provide additional verification for purchases made online or over the phone, CVV numbers help keep transactions safe.

2020年6月21日 · 数据传输至银行后，银行看到是 CVV2 码，就知道这是 card not present 交易。 再深入一点的话，银行区分是否是 card present 交易的最重要原因就是风控了。 一般 card present 的交易，风控标准会稍低一点，毕竟你是当面进行结算的，是暴露在公众甚至于摄像头之下的。 如果 card not present，风控要稍微严格一点，因为打电话或者网上交易，发生 fraud 的概率要大不少。 至于为什么有卡号和过期时间验证的情况下，还要弄一个安全码呢？ 因为大多数商家为了 …

2020年3月15日 · The CVV number on an AMEX is the four digits above the last few digits on the front of the card (see below) and is what you need to enter when processing a payment. “CVV is an anti-fraud security feature to help verify that you are in possession of your credit card.

2022年9月19日 · When you are asked to provide your CID/CVV (or main security code) for your card, you will input the four digit number on the front of the card. But other situations will arise when you need to provide the three digit code on the back of an American Express card. Typically, you will only have to do this when dealing with American Express.

2023年1月10日 · A CVV2 code is a three-or-four digit number printed on the back of credit cards, debit cards and prepaid cards (or the front of Amex cards) that you have to provide for security purposes when making a purchase online or over the phone.

2021年11月24日 · For Mastercard, Visa, and Discover credit cards, the CVV code is three digits, and it's located on the back of the card near the signature line. On American Express cards, the CVV code is four digits long, and you'll find it on the front of the card.

2021年5月21日 · The CVV2 is a three- or four-digit code printed on the front or back of your credit or debit card. You'll need to provide the CVV2 for many online and phone transactions. The code helps protect against fraudulent transactions by providing proof that you're in possession of your card at the time of purchase.

Card Verification Value (CVV2, sometimes called "Card Verification Code" or CVC2) is a three or four digit number printed on a payment card to help prevent fraud when accepting a purchase online or over the phone (also known as a card-not-present transaction).