Credit card numbers explained (2024)

This is often referred to as the ‘long number’ on the front of your credit card, which is usually 16 digits, but can be up to 19 digits in some instances. More formally, it’s known as a Permanent Account Number, or ‘PAN’.

It’s not just a random number though. Your credit card number is unique to you and includes information used to identify your account, card and who it’s issued by.

The first digit indicates the provider:

• Mastercard numbers start with a 2 or 5.
• Visa card numbers start with a 4.
• American Express numbers start with a 3.

The first 6 digits help to identify the card issuer, known as an Issue Identifier Number or ‘IIN’.

All numbers following that relate specifically to your account, excluding the last one which is known as a ‘check digit’. This helps us verify that the full credit card number has been provided, and in the right order, anytime you make a purchase or payment.

This method for creating credit card numbers is used internationally, and was invented by IBM engineer Hans Peter Luhn in 1954.

These numbers represent the month and year your card was issued, and when it will expire. For example, 06/20 would be June 2020.

Credit cards are typically issued for 2 to 4 years, and renewed just before the expiry date. You might notice that the ‘expires end’ date is 3 years and 1 month after the ‘valid from’ date, just giving you a little extra time to switch to your new card.

Once it’s expired, you won’t be able to use your old card, so it’s a good idea to start using a new card as soon as it arrives, just to avoid any future inconvenience.

If your credit card is re-issued for any reason, e.g. you’ve ordered a replacement for a lost card, as you’d expect, your new card will have revised ‘valid from’ and ‘expires end’ dates.

For security, any old cards should be cut up and disposed of carefully.

When you make a purchase online or over the phone, you may be asked for the ‘CVV’, ‘CVC’, ‘CVN’, ‘CVV2’ or a ‘security number’. In reality, they’re all the same thing.

In simple terms, it’s a card verification number or code. Because it’s only ever printed on the card itself, when you provide it, that helps us to verify the physical card is still in your possession.

On Visa and Mastercard credit cards, you’ll find your security number on the back of your card. It’s the last 3 digits of the number printed in the top right-hand corner of the signature strip.

On American Express credit cards it’s a 4-digit number printed on the front, just above and to the right of the long credit card number.