Even seasoned credit card users may not be fully aware of the underlying mechanisms. A recent discussion on X (formerly Twitter) by a software engineer, who is also a solution architect, shed light on credit card number functionalities. FinPal also contributed to the discussion on X, focusing on how online platforms such as Amazon and Flipkart instantly validate credit card numbers and identify relevant bank offers. FinPal clarified that credit card numbers are generated through a concealed algorithm to ensure rapid validation and seamless banking operations.
Banks use the Luhn Algorithm to verify the credit card numbers provided by users. This algorithm assesses if the sum of all digits (with every second digit doubled) is divisible by 10. A divisible sum validates the credit card number. Banks utilize the BIN (Bank Identification Number) system, with the initial 6 to 8 digits indicating the card issuer. Portals then use the BIN range to check for applicable card offers. The first digit conveys the Major Industry Identifier (MII), identifying the card network. The first 6-8 digits are the BIN (Bank Identification Number), providing information about the bank and the specific card type, such as Visa Infinite or HDFC Infinia.