Payment Card Glossary

Identifier terms

The identifiers are the foundation. The IIN, formerly the BIN, is the leading block of a PAN allocated to an institution. The PAN is the full account number. The check digit is derived from the digits before it. Length varies by network and product.

• IIN - the issuer identifier at the start of a PAN
• BIN - the former name for the IIN
• PAN - the primary account number
• Check digit - derived from the preceding digits
• Account identifier - the issuer-assigned middle portion

Record format terms

Records come in several shapes. Track 1 and Track 2 are the magnetic stripe formats. A cryptogram is generated by the chip. A token substitutes for the PAN. An EMV record is a tagged, nested structure.

• Track 1 - alphanumeric stripe record including the name
• Track 2 - numeric stripe record
• Cryptogram - chip-generated proof of a genuine transaction
• Token - a substitute identifier for storage
• TLV - tag, length, value encoding used in EMV

Authorisation and settlement terms

Authorisation is the real-time check that decides whether a transaction proceeds. Clearing is the later netting of transactions. An approval code is the issuer's reference. A response code explains the outcome. A dispute is a chargeback initiated by the cardholder.

• Authorisation - the real-time decision to proceed
• Clearing - the later netting of transactions
• Approval code - the issuer's reference for an approved authorisation
• Response code - the reason for the outcome
• Dispute - a chargeback raised by the cardholder

Network and risk terms

The risk vocabulary describes how a transaction is judged. A 3DS challenge is a cardholder authentication step. Velocity limits cap how often a card may be used. An attempt counter records failed attempts. Fraud scoring rates a transaction before authorisation.

• 3DS challenge - a cardholder authentication step
• Velocity limit - a cap on usage frequency
• Attempt counter - a tally of failed attempts
• Fraud score - a pre-authorisation risk rating
• BIN range - the block of prefixes an issuer holds

How to use this glossary

Each entry states what the term is, which standard it comes from and why it matters in practice, with a link to the guide that covers it in depth.

• Every entry links to the relevant guide
• Standards references are given where they apply
• Terms are grouped by the layer they belong to
• Plain definitions with practical consequence