Track 1 is a special data set encoded on a card's magnetic stripe that contains the card information required for authorization when the card is used physically. It includes the cardholder name, card number, and expiration date.
It is alphanumeric and 79 characters long.
The fact that our name appears on the screen when we insert a card into an ATM, and that the cardholder's name is printed on the POS receipt for transactions made through a POS terminal, is the result of the ATM and POS device reading the cardholder name from the Track 1 data.
Track 1 field structure
| Field Description | Length | Length Description |
| Start Sentinel (SS) | 1 character | The delimiter indicating that Track 1 begins. It starts with “;”. |
| Format Code | 1 character | Starts with B. |
| Card Number | Up to 19 digits | This is the card number. It is typically 16 digits but can be up to 19 digits. |
| Separator | 1 character | Used to separate Track 1 fields. The ^ character is used. |
| Cardholder Name | 26 characters | This is the cardholder's full name. |
Separator | 1 character | Used to separate Track 1 fields. The ^ character is used. |
| Expiration Date | 4 digits | Stored in YYMM format. |
| Service Code | 3 digits | Holds information such as the card type, PIN usage requirement, and domestic/international usage restrictions. |
| Discretionary Data | Variable | Its content is determined by the issuer. It includes the following: PVKI: PIN Verification Key Indicator PVV or Offset: PIN Verification Value CVV or CVC: Card Verification Code/Value |
| End Sentinel (ES) | 1 character | Indicates that Track 1 ends. It is set as “?”. |
| Longitudinal Redundancy Check (LRC) | 1 character | Used to confirm that Track 1 was read without errors. |
Examining Track 1 data through an example
%B1234567890123445^UNAL/ARIF ^23071260000000000000**XXX******?*^^^ ^^ ^^ ^ ^ ^ ^^|||_ Card number ||_ Card holder || | | |_ CVV** ||_ LRC||_ Format code |_ Field separator || | | |_ End sentinel|_ Start sentinel Field separator _|| | |_ Discretionary data Expiration _| |_ Service code
- % = Start of Track 1
- B = Format Code
- 1234567890123445 = Card Number
- ^ = Field separator
- UNAL/ARIF = Cardholder Name
- ^ = Field separator
- 2307 = Expiration Date
- 126 = Service Code
- 0 = PVKI (PIN Verification Key Indicator)
- 00000000000 = PVV (PIN Verification Value)
- XXX = CVV (Card Verification Code)
- ? = End of Track 1
- * = LRC