What do the long numbers on your credit or debit card mean?

You’ve probably never thought about what the long number on your credit or debit card means. After all, you’ll only ever have looked at it when making purchases online, but this long number contains quite a lot of information about your account. So that you know what it all means, we’ve put together this guide.

The first digit

The first number tells you the major industry that produced the card. Depending on your card, this could be either one of the following:

3 – cards issued with a number 3 as the starting digit are typically travel or entertainment cards. In the UK, one of the few cards to use this starting number is American Express but it’s more frequently used in the U.S.

4 – Visa

5 – MasterCard®. If you’re a thinkmoney customer, this is the starting number you should see on your thinkmoney Prepaid Debit MasterCard®.

6 – typically used on American cards.

Card structure

In general most card issuers will structure the long number (also known as a Permanent Account Number or PAN) in the following way. The six digits on the card including the first number (which in this case is 5) provide a unique identifier for a particular institution. This is called the issue identifier number or IIN. Digits 7 to 15 identify the person that holds the account – you. But don’t worry, this number doesn’t expose anything about you or your information, it’s simply allocated to you by the card issuer and is completely unique to them.

The last digit is called a check digit and is used to validate the authenticity of the number. To put it simply, when an algorithm is applied, this number verifies that the full credit card number has been read or inputted correctly.

Back of the card

When making purchases online, you’ll be asked to input your CVV number for the transaction to go through. This three-digit number can be found on the back of your card – it’s usually located near the signature strip and highlighted in italics. In front of this, there should be another four digit number which should be identical to the last four digits on the front of your card. When looking at our thinkmoney example, this is ‘7890’.

Changes to the thinkmoney Prepaid Debit MasterCard®

If you’re a thinkmoney customer, you should be aware by now that there are going to be changes to the thinkmoney Prepaid Debit MasterCard. In accordance, with the Post Office changes, we’re issuing all customers with a new thinkmoney card from October onwards.

The new thinkmoney Prepaid Debit MasterCard will look relatively the same, but you’ll notice that your new card carries your account number and not your thinkmoney reference. Over the next couple of months, we’re going to be phasing out reference numbers so please remember to enter your account number when logging in or calling us.

The long number (PAN) and your PIN will remain the same, but your card expiry date and the three digit CVV code on the back will change.