Overview
EMV is the global standard for secure chip-card payments.
EMV stands for Europay, Mastercard, and Visa. The EMV specs define how cards, terminals, and payment networks exchange data during chip and contactless transactions. Instead of raw magnetic stripe data, EMV uses structured data objects called tags. Each tag has a code (like 9F02), a defined meaning, and specific formatting rules.
Understanding EMV tags helps with terminal certification, log analysis, and dispute investigation. It also helps product teams confirm that the right data is flowing to acquirers and issuers.
What is a tag?
A tag is a data element inside an EMV message. Tags are encoded in TLV format (Tag-Length-Value). Each tag has a fixed meaning such as transaction amount, terminal capabilities, or cryptogram data.
Why tags matter
Issuers and networks rely on tags to decide whether to approve a transaction, which CVM to use, and how to score risk. A single bit change in a tag can alter the outcome.
Next step: explore the tools
Use the interactive parser to inspect real EMV tag values or build a tag from bit selections.