What Is a CID Number on a Credit Card?

A Card Identification (CID) number on a credit card is a security feature. It helps protect consumers from fraudulent activity by verifying the cardholder’s identity during transactions where the physical card is not present. This enhances the security of purchases made online, over the phone, or through mail order.

Understanding the CID Number

The CID number is a three or four-digit security code found on credit cards. Its fundamental purpose is to act as an anti-fraud measure, helping to verify that the individual making a purchase is the legitimate cardholder. This number is unique to each card and is not typically embossed like the primary account number or expiration date. Unlike other card details, the CID number is not stored by merchants after a transaction is completed, which makes it more difficult for fraudsters to compromise. This adds a significant layer of security for “card-not-present” transactions.

Locating the CID Number

The placement of the CID number varies depending on the credit card brand. For Visa, MasterCard, and Discover cards, the CID is a three-digit code located on the back of the card. This code is found within or near the signature strip, immediately following the credit card account number. American Express cards feature a four-digit CID number. This four-digit code is printed on the front of the card, often positioned above and to the right of the main credit card number.

Using and Protecting Your CID Number

The CID number is requested during transactions where the physical card is not present, such as online shopping, telephone orders, or mail-order purchases. Merchants request this number to verify the cardholder’s identity, ensuring the person using the card has physical possession. This helps prevent unauthorized use, especially in digital environments.

It is important to keep your CID number confidential. Never share it with unauthorized individuals or respond to suspicious requests. Securely disposing of old credit cards by shredding them also prevents fraudsters from obtaining your CID or other sensitive card details.

Merchants are prohibited from storing your CID number after a transaction, as mandated by Payment Card Industry Data Security Standard (PCI DSS) requirements. This minimizes the risk of data breaches and fraudulent activity. Be vigilant about phishing attempts, which are fraudulent communications. Always ensure you are on a secure website, indicated by “https” in the address bar, before entering any card details.

Common Terms for Credit Card Security Codes

The CID number is known by several different names depending on the credit card network. Visa often uses Card Verification Value (CVV) or CVV2. MasterCard refers to its security code as a Card Validation Code (CVC) or CVC2. American Express uses Card Identification Number (CID), and Discover also sometimes uses CID. Other general terms include Card Security Code (CSC) or Card Security Value (CSV); each provides an additional layer of security for card-not-present transactions by confirming the card’s authenticity.