TSI Decoder
Decode the EMV Transaction Status Information (tag 9B) bitfield — the functions the terminal and card actually performed during a transaction.
What the Transaction Status Information (9B) records
The Transaction Status Information (TSI), EMV tag 9B, is a 2-byte bitmap that records which EMV functions were actually performed during a transaction. It is the card-and-terminal's audit trail: offline data authentication, cardholder verification, card risk management, issuer authentication, terminal risk management, and issuer script processing each have a bit that is set once that step runs.
Read the TSI alongside the TVR. The TVR says what went wrong; the TSI says what was done. Together they answer the two questions every EMV investigation starts with — "which checks ran, and which of them failed?"
Reading the bits
All defined flags live in byte 1; byte 2 is reserved for future use and is normally 00. A common diagnostic pattern is "Offline data authentication performed" set while the matching TVR bit reports it failed — that tells you authentication ran and was rejected, rather than being skipped because the terminal or card did not support it.
Common questions
The TSI shows no CVM performed — is that a problem?
Not necessarily. On a low-value contactless tap, no-CVM is the expected outcome. It only matters when the transaction value or terminal configuration required verification.
Why is "Issuer authentication performed" not set on an online txn?
Issuer authentication only runs if the issuer returned an ARPC and the card requested it via the AIP. A missing bit here often points to the host not sending issuer authentication data back.
Bit definitions follow EMV Book 3. All decoding happens locally in your browser.