Despite years of credit card usage, many people are still unaware of the intricacies involved. A software engineer, employed as a solution architect, who is also a passionate online shopper, shared a thread on X (formerly Twitter) discussing how credit card numbers are structured. FinPal also contributed on X, highlighting how online platforms such as Amazon and Flipkart can immediately ascertain whether a credit card number is valid and identify associated bank offers. Credit card numbers are not randomly assigned; they are generated using a concealed algorithm to streamline rapid validation and banking operations, according to FinPal.
Credit card numbers are verified using the Luhn Algorithm by banks. This algorithm confirms if the sum of all numbers, calculated by doubling every second digit, is divisible by 10. If the sum meets this criterion, the credit card number is deemed valid. Banks utilize the BIN (Bank Identification Number) system. The initial 6 to 8 digits indicate the card issuer, which allows portals to determine available offers by referencing the BIN range. The initial digit reveals the Major Industry Identifier (MII), identifying the card network, while the first 6-8 digits represent the BIN, indicating the bank and card type, such as Visa Infinite and a specific card like HDFC Infinia.