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 ...

Choosing the right cash-back credit card can lead to some quick savings. You can earn hundreds in cash-back rewards annually based on your spending. Are you ahead, or behind on retirement?

How much does credit card debt really cost you? Most people don’t even want to think about it, let alone do the math themselves. But with the federal reserve’s free and simple credit card repayment ...

Out of habit, I pulled a credit card from my wallet — I figured I’d earn rewards on this pricey transaction — but then the tech warned me that his company assesses a 3% surcharge on credit card ...