What Card Starts With a 5 and What Do Others Mean?
Understand how the initial digits of payment card numbers identify their network and enable efficient, secure transaction routing.
The numbers present on credit and debit cards are not random sequences. These digits are carefully structured to convey specific information about the card, including the network it belongs to and the institution that issued it. Understanding the initial digits of a payment card number helps to identify its origin and how it functions within the global financial system. This structure allows for efficient processing and routing of transactions across various payment networks.
The “5” Prefix: Identifying Mastercard
Payment cards that begin with the digit ‘5’ are issued through the Mastercard network. This leading digit is part of what is known as the Bank Identification Number (BIN) or Issuer Identification Number (IIN), which comprises the first four to six digits of a credit or debit card number. The ‘5’ specifically designates the card as being affiliated with Mastercard, a global payment technology company.
Mastercard facilitates electronic funds transfers between banks and merchants around the world. Its network enables consumers to make purchases at millions of locations globally, both in person and online. The consistent use of the ‘5’ prefix provides immediate identification within the payment processing infrastructure, ensuring transactions are correctly routed.
Beyond “5”: Other Major Card Prefixes
While ‘5’ identifies Mastercard, other major payment card networks also use distinct initial digits or ranges. For instance, cards starting with the digit ‘4’ are part of the Visa network, which is a global payment system. Visa cards are issued by various financial institutions and are used for transactions worldwide.
American Express cards begin with the digits ’34’ or ’37’, distinguishing them as part of their proprietary network. The JCB network, primarily based in Japan, also uses prefixes starting with ’35’. Discover cards are identified by prefixes such as ‘6011’, ‘644’ through ‘649’, or ’65’. These specific ranges help payment systems quickly recognize the card’s network. Other networks like Diners Club and UnionPay also have their unique starting digits.
The Purpose of Card Number Prefixes
The initial digits of a payment card, known as the Bank Identification Number (BIN) or Issuer Identification Number (IIN), serve a purpose in payment processing. These prefixes, typically the first four to six digits, identify the card’s network and the specific financial institution that issued the card. This identification is crucial for routing transactions from a merchant’s terminal to the correct payment network and then to the cardholder’s issuing bank for authorization.
Beyond routing, BIN/IINs also play a role in security and fraud detection. Payment systems use these prefixes to validate the card type and ensure it aligns with the transaction being processed, helping to flag suspicious activities.