I’m always surprised when I give people my credit card number and then they ask me if it’s a Visa or MasterCard. These thing have some logic behind them but everybody doesn’t know the secrets to the codes.
If you reach into your wallet you’ll find that all your Visa cards will begin with a 4. All your MasterCards will begin with a 5. American Express typically begins with 34 or 37 and Discover usually starts with a 6011, 644, or 65.
That little combination on your credit card tells still a bigger story. Not only does it identify the type of card but it uses itself to make sure the number os real.
And the code to check a credit card is so simple, it’s brilliant.
Cards are specifically identified by their Issuer Identification Number (IIN). The first six numbers on the card identify exactly who issued the card.
Here is a great graphic that was put out by Mint.com to help explain this even further.
Right about now I bet you’re reaching for your wallet to check your own cards. If you want to check out this information, pull out on of your Visa or MasterCards and use the first six numbers to confirm your IIN, here.