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Have you ever wondered what all the numbers on the front – and back – of your credit card mean?
For the set of numbers that millions of people encounter in close-ups every day, many of us have little or no understanding of what the numbers relate to and what they represent.
Our guide explains more about the importance of the numbers printed on your credit card.
How to read your credit card number
The long number on the front of your card contains important information. The sequence of digits is not random but is actually set according to international standards. The same system is used worldwide and was invented in 1954 by IBM engineer Hans Peter Luhn.
From this sequence of numbers, it is possible to find out the issuing bank, the cardholder’s personal account number – and much more. But most importantly, the technology behind long numbers helps prevent fraud, reduces payment issues, and potential errors.
What does the long number on my card mean?
While it may seem random, each credit card digit is strategically placed and each represents important information.
The long number – usually the 16 digits on the front of your credit card – is called a permanent account number, or PAN.
This number is unique to you and your card account and includes information used to identify the payment network used, the card issuer (bank or lender) and your personal card account.
The first digit indicates the card payment network used – that is, American Express, Mastercard or Visa:
- Master card numbers usually start with a two or five
- Visa card numbers usually start with a four
- American Express numbers start with a three
First six digits
The numbers from one to six in long digits identify the card payment network and card issuer. This is called the IIN problem identifier number.
The numbers from seven to 15 identify you, the holder of the card. This is your card issuer’s way of identifying you and your card account so this number is unique to you.
Credit cards need to be used instantly for payment. That’s why the validation process that banks use must immediately encrypt and decrypt sensitive data.
Credit card issuers and networks use mathematical tools to combat data breaches and other fraudulent activity. Luhn’s algorithm (Hans Peter Luhn) is one such device. Developed in the US in the 1960s, it uses an identifying digit to determine its validity.
The last digits of the long number on your credit card are used in this way to validate the entire number. Effectively this final number is used to verify that the full credit card number has been read or typed correctly (eg when making an online payment).
Back of credit card
There are a number of features that you would normally find on the back of a credit card:
- Security code (CVV)
- Magnetic line
- A hologram
- Bank contact details and customer service telephone lines
- A signature box
- Card network logo (eg Mastercard or Visa)
- Some credit cards have an expiration date on the back.
Other card numbers: CVV and expiration date
CVV number – card verification value (or sometimes CVC, card verification code) – usually a three-digit number located on the back of your credit card. This number represents a validation or other check process – adding another layer of fraud protection.
When you buy something online or over the phone using your card, the retailer or merchant will usually ask for your CVV number. This small but significant piece of information provides more assurance that the account owner owns the card – and that the number is not stolen for fraudsters to use.
Expiration date – this number is assigned to the card by the issuing bank or lender. It can also help with security by requesting another verification step when making a purchase.
A card number may have been stolen, but without a CVV and expiration date, it becomes nearly worthless.
Chip and PIN technology and magnetic stripe
All of these numbers – PAN, CVV/CVC, and expiration dates – are stored on the magnetic strip on the back of your credit card. Also known as a magstripe, the magnetic stripe transmits card data to the point of sale. The data transmitted is static, which means the information is loaded onto the strip and remains unchanged for the life of the card.
While most plastic cards still have a magstripe, the majority now use Chip and PIN and contactless technology as the main way to pay for goods and services.
Chip technology is placed on the face of the card to transmit data to the point of sale. But unlike the static information on a magnetic strip, chip technology is more dynamic. Each time you use the card, the transaction generates a different one-time code. Chips and PINs are therefore much more secure for card issuers and cardholders – because card counterfeiting is much more difficult.
It’s expected that most card issuers will start removing the magnetic stripe on the back of all plastic cards in the coming years. Chip and PIN and increasingly, contactless payments, are now the main way consumers pay for things.
Contactless payments, which can be used to pay for goods and services directly up to £100, can be made using a card with a contactless symbol or a smartphone (where the phone account is linked to the account owner’s bank account).
According to figures published in February 2023 by UK Finance, the trade body representing the banking industry, 60% of all credit card transactions and 74% of debit card payments are now contactless.
Banks and other card issuers are looking into biometric payment systems, which could enable facial recognition and palm scanning, among other technologies, to better crack down on fraud.
Credit card number versus account number
Many people mistakenly think that the number on the front of their credit card is the same as their account number. But even though the numbers are connected, they are not the same. You will find your card account number on your credit card statement.
If you need to replace your credit card, whether it is stolen, damaged or lost, you will receive a new card number, but your account number will remain the same.
Customer service phone line
A customer service phone line is not required to make purchases and plays no role in keeping your card safe from fraud. But they are still the best way to contact someone from your bank when you need them, for example in the event of an emergency such as a lost or stolen card.
For example, many fraud attempts are made over the phone or by e-mail. The quickest way to check if a call or message is legit is to call the number on the back of your card. This way you know you will be talking to someone from your bank who can find out if a message has been sent to you.
Write this number down or put it on your phone so if you lose your card you can call immediately to block the card immediately and prevent payment fraud.
Hologram security feature
Holograms are hard to fake, which is why they can be a great security feature. This small, mirror-like patch, usually on the back of your card, displays a three-dimensional image.
If you look closely, you’ll see the hologram image move as you change the viewing angle. This can be another way for merchants and retailers to check the authenticity of cards.
How to protect your credit card number
It is important to be vigilant and remember that credit card numbers are always stolen and fall into the wrong hands. The best thing you can do to avoid this is to be careful every time you use your card.
- When shopping online, pay attention to the retailer or merchant. If possible, use a service like Paypal that keeps your credit card number secure. If not, check the legitimacy of the company and website, and make sure the web page is secure (look for things like urls that start with https and should have a padlock symbol next to them)
- Watch out for phishing emails and be on the lookout for scam phone calls — this is where scammers might email or call you, claiming to be from your bank or credit card company and asking for security information. Never provide this information over the phone or email. If the email looks suspicious, don’t click any links and don’t download attachments. Verify sender or contact your bank immediately
- Make sure your computer is protected against malware and spyware, this is the name of software that crooks and fraudsters can use to illegally obtain information about your bank and card accounts from your computer’s hard drive
- Be aware of the latest new scams and tricks fraudsters may use to steal your financial information and card details.
Frequently Asked Questions (FAQs)
What is a credit card number?
A credit card number is a long string of numbers, usually 16 digits, that is usually displayed on the front of a credit card. Its purpose is to identify credit card issuers and account holders. This can also help prevent fraud.
How long is a credit card number?
Credit card numbers are usually 16 digits long.
How do people steal credit card numbers?
Phishing emails and vishing calls are still one of the most common methods of theft. Spyware and malware are also increasingly common.
This is where criminals use software to obtain personal financial information from a person’s computer by surreptitiously sending data from their hard drive.
And don’t forget the good old fashioned way – looking through your trash. If you receive a paper statement from your bank, make sure you shred it or remove any card numbers before you throw it away.