What Is a CID on a Credit Card and How Does It Work?
Understand the critical security code on your credit card. Learn how your Card Identification Number protects online purchases and enhances transaction safety.
Credit cards are a common tool for managing finances and making purchases. To ensure transaction safety, they incorporate security features designed to protect cardholders and financial institutions from unauthorized use.
Understanding the Card Identification Number
A Card Identification Number (CID) is a security code designed to protect credit and debit card transactions, especially those where the physical card is not presented. It functions as a fraud prevention tool, confirming legitimate card access. This number is distinct from the primary card account number and expiration date.
The CID is known by several names depending on the card network. For instance, Visa refers to it as a Card Verification Value (CVV), while Mastercard uses Card Validation Code (CVC). Other common variations include CVV2, CVC2, and CID. These codes were introduced around 2000 to enhance security for online and phone transactions.
Locating Your Card Identification Number
Finding your Card Identification Number (CID) on a credit or debit card is straightforward, though its placement and number of digits vary by card network. For Visa, Mastercard, and Discover cards, the CID is a three-digit number located on the back of the card. It is found in or near the signature strip, often immediately following part or all of the main card number.
American Express cards feature a four-digit CID, found on the front of the card. This number is printed above the main account number, often on the right side. Regardless of the card type, the CID is printed, not embossed, which helps differentiate it from the raised numbers of the primary card account.
How the Card Identification Number Enhances Security
The Card Identification Number (CID) adds a layer of protection by verifying physical card possession. This security measure is effective for “card-not-present” transactions, such as purchases made online or over the phone. By requiring the CID, merchants confirm the card’s authenticity and reduce fraudulent activity.
Merchants are prohibited from storing the CID after a transaction is authorized. Unlike the main card number and expiration date, which may be stored for recurring payments, the CID must be removed from the merchant’s system. This policy reduces the risk of fraud if a merchant’s database is compromised, as criminals would not gain access to the CID needed for future unauthorized purchases. The non-storage rule means that even if other card details are stolen, the absence of the CID makes it much harder for fraudsters to complete transactions. The CID is not encoded in the card’s magnetic stripe, further protecting it from skimming devices.
Using Your Card Identification Number for Transactions
When making purchases where your credit card is not physically swiped or inserted, you will be prompted to provide your Card Identification Number (CID). This applies to online shopping, telephone orders, and mail orders. Entering this code ensures an additional layer of verification for these “card-not-present” transactions.
For online purchases, you will find a dedicated field on the payment page labeled “CID,” “CVV,” “CVC,” or “Security Code.” Input the three or four-digit number from your card into this field. When placing an order over the phone, the customer service representative will verbally request the CID along with your card number and expiration date. Providing this number helps confirm you are the legitimate cardholder during the transaction process.