56
Track 1 DataTrack 1 Data is the chip-carried copy of magnetic-stripe track 1 as defined by ISO/IEC 7813, minus its start/end sentinels and LRC checksum, which the terminal reconstructs itself rather than reading from the card. It plays the same backward-compatibility role for track 1 that Track 2 Equivalent Data (57) plays for track 2, and the two are related precisely because a terminal reconstructing full legacy magnetic-stripe-equivalent data for a host that still expects it needs both tracks, not just one. This is specifically a Kernel 2 tag, scoped to Mastercard PayPass contactless transactions per the card's own brand data - a reader built for a different kernel won't encounter tag 56 at all, and its absence there isn't a defect, just a different kernel's data model. Because 56 carries the same category of magnetic-stripe-equivalent cardholder data as 57, it deserves exactly the same handling discipline: never logged or displayed in full, and cross-checked against 57's own embedded PAN if the two ever need to be compared for consistency. See EMV Contactless Book C-2.
Interactive decoder
Paste a hex value for this tag to decode it in your browser. Nothing is sent anywhere.
Text (ASCII): TEST/CARDHOLDER
This tag is not a bitmap; the decoder shows a format-based interpretation.
Decoded example
Example value: 544553542F43415244484F4C444552
Properties
| Tag | 56 |
|---|---|
| Name | Track 1 Data |
| Format | Alphanumeric (special) |
| Length | variable |
| Source | Card (ICC) |
| Templates | 70 |
| Books | EMV Contactless Book C-2 |
Frequently asked questions
- What is EMV tag 56?
- Track 1 Data is the chip-carried copy of magnetic-stripe track 1 as defined by ISO/IEC 7813, minus its start/end sentinels and LRC checksum, which the terminal reconstructs itself rather than reading from the card. It plays the same backward-compatibility role for track 1 that Track 2 Equivalent Data (57) plays for track 2, and the two are related precisely because a terminal reconstructing full legacy magnetic-stripe-equivalent data for a host that still expects it needs both tracks, not just one. This is specifically a Kernel 2 tag, scoped to Mastercard PayPass contactless transactions per the card's own brand data - a reader built for a different kernel won't encounter tag 56 at all, and its absence there isn't a defect, just a different kernel's data model. Because 56 carries the same category of magnetic-stripe-equivalent cardholder data as 57, it deserves exactly the same handling discipline: never logged or displayed in full, and cross-checked against 57's own embedded PAN if the two ever need to be compared for consistency. See EMV Contactless Book C-2.
- What format and length does EMV tag 56 use?
- Tag 56 uses the Alphanumeric (special) format and is normally variable long.
- Is tag 56 provided by the card or the terminal?
- Tag 56 (Track 1 Data) is provided by the Card (ICC).
Sources
- C-2-Kernel-2-V2.11-Final-June-2023, p. 429
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