The Daily Overview on MSN

Walmart and Target can now reject your credit card. Here is what shoppers must know

Retailers now have fresh power to say no when you swipe, even if your credit card is valid and your account is in good ...
Scientific American

The Math Trick Hidden in Your Credit Card Number

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 ...