Finder is committed to editorial independence. While we receive compensation when you click links to partners, they do not influence our content.
What do credit card numbers mean?
Credit card numbers are not just random identification numbers. They determine how each transaction will be routed and enhance security.
Updated . What changed?
You probably know your credit card numbers by heart, either in full or the last four digits, yet have no idea what they mean. The numbers each have a specific identification function either for the bank, the system or you personally.
While it is not imperative to spending that you know what the numbers mean, it is food for thought that helps you understand the process your information goes through with each credit card transaction. Let’s take a look.
What is a credit card number?
A credit card number is the long set of digits displayed on the front or back of your plastic card. Typically, the numbers are 16 digits long and appear in groups of four. Credit card numbers aren’t assigned at random. Instead, they are coded to help reduce the risk of thieves being able to guess your details and commit fraud.
Unlike other account numbers such as gas, phone company or department stores, all credit cards use the same number system. Almost all national credit card numbers are based on the ANSI Standard X4.12-1983 system. In this system, the number and structure of the numbers on the card indicate what kind of card it is and to whom it belongs.
Credit card numbers breakdown
- The first number on your credit card notes the system that your card belongs to. Each of the major credit cards is assigned to a system.
- Number 6 denotes a Discover credit card
- Number 5 denotes a Mastercard
- Number 4 denotes a Visa
- Number 3 denotes a travel or entertainment card like American Express or Diners Club
- Within each system is a structure that is unique to that credit card company. For example:
- On American Express cards the third and fourth digits are type and currency, the fifth through the eleventh digits are the account number, the twelfth through the fourteenth digits are the cards number within that particular account, and the fifteenth digit is the check number.
- A Visa uses digits two through six for the bank number, the seventh digit through the twelfth or the fifteenth are the account number and digit thirteen or sixteen is the check number.
- Mastercard uses digits two through six as account numbers depending on the length it can be digits two and three or two through four or two through five or six. After the bank number the digits that follow up to the fifteenth are the account number and the sixteenth digit is the check number.
While it is more important to know where you are spending your money then the function of your credit card numbers it is helpful to understand the complexities of the credit card system. Once you realise how much effort has gone into ensuring credit card security and efficiency, you will have more appreciation for your card.
More guides on Finder
DBS credit card promotions 2021
We have covered the latest DBS credit card promotions, welcome offers and rewards to help you narrow down on your search.
Guide to opening a bank account in Singapore for international students
If you’re an international student in Singapore, having a local bank account can help you manage your finances with ease.
Debit cards vs ATM cards
ATM and debit cards are often the first plastic card you’d gain access to. But what’s the difference between these two cards?
Online shopping debit cards
Learn more about the rewards and perks that come with online shopping debit cards in this guide.
Debit cards with instalment payment plans
Learn more about splitting large upfront costs and if your debit card is eligible for instalment plans.
Guide to using debit cards overseas
Using your debit card in a foreign country is safe and convenient, but make sure to enable it for overseas use and look out for fees.
Best Visa debit cards
Make payments conveniently at over 61 million merchants across the world with a Visa debit card. Find out which banks in Singapore offer them.
POSB Digital Banking review
POSB digital banking helps you manage your money anytime, anywhere.
OCBC debit cards
Discover the features and perks offered by the various OCBC debit cards.
Guide to GrabPay
Streamline your payments with GrabPay, a mobile wallet and payment solution offered by Grab.