Card & BIN glossary
Plain-English definitions of the payment card terms you’ll meet across our tools.
- BIN (Bank Identification Number)
- The first 6-8 digits of a card number, identifying the network, issuing bank, card type and country. Now often called the IIN.
- IIN (Issuer Identification Number)
- The modern ISO term for the leading digits of a card number — the same thing as the BIN.
- PAN (Primary Account Number)
- The full card number, 12-19 digits. The BIN is just its first 6-8 digits; the last digit is the Luhn check digit.
- Issuer
- The bank or institution that issued a card to a cardholder.
- Card network (scheme)
- The system that routes and processes a card transaction — for example Visa, Mastercard, American Express, Discover, RuPay, JCB or UnionPay.
- Luhn algorithm (mod 10)
- A simple checksum (ISO/IEC 7812-1) that validates a card number's final check digit and catches most typos.
- Check digit
- The last digit of a card number, calculated so the whole number passes the Luhn checksum.
- Prepaid card
- A card loaded with a fixed balance rather than linked to a credit line or bank account.
- Credit vs debit
- Credit cards draw on a line of credit; debit cards draw directly from a linked bank account. The card type is often encoded in the BIN.
- CVV / CVC
- The short security code on a card (3 digits for most networks, 4 for American Express), used to verify card-not-present transactions.
- Tokenization
- Replacing a card number with a surrogate 'token' so the real number isn't stored or transmitted by merchants.
- ISO/IEC 7812
- The international standard that defines card number structure, including the IIN and the Luhn check digit.
- Test / sandbox card
- A synthetic, non-functional card number that passes format checks, used to test software without real payment data.