All mainstream credit card numbers obey a mathematical trick designed to catch the most common typos. It’s called the Luhn algorithm, named after IBM researcher Hans Peter Luhn, who patented it in ...

You’re at the checkout screen after an online shopping spree, ready to enter your credit card number. You type it in and instantly see a red error message ...

The numbers on a credit card help identify the credit card network, the company that issued the card and the cardholder. Credit card numbers are either 15 or 16 digits, with each digit having its own ...

Most of us use credit cards regularly, but very few know how these cards actually work. Recently, a software engineer and online shopping enthusiast shared an X (formerly Twitter) thread explaining ...