Track 2 Data — Technical Overview (and Why It’s Slowly Disappearing)Track 2 is the numeric-only magnetic-stripe data format defined in ISO/IEC 7813, with a maximum length of 40 characters.

The discussion here complements the broader POS and EMV architecture material in POINT OF SALE ARCHITECTURE — Volume 1: A Practical Guide to Secure, Certifiable POS Systems ( the book), which should be treated as the primary reference for system-wide design and security considerations.

Its structure is: SS PAN FS ED SC DD ES LRC

Where:

• SS — Start sentinel ;
• PAN — Primary Account Number (up to 19 digits)
• FS — Field separator =
• ED — Expiry date (YYMM)
• SC — Service code (3 digits)
• DD — Issuer discretionary data (PVKI, PVV, CVV, iCVV, or other issuer-defined values)
• ES — End sentinel ?
• LRC — Longitudinal redundancy check (optional in some implementations)

Real-world example: 4761739001010119=25122011143804400000

Track 2 in a POS Transaction

This diagram shows the structure and purpose of Track 2 data in payment cards. It highlights that Track 2 contains the PAN, expiry date, service code, and possible issuer discretionary data, and explains how these fields are used for cardholder identification, routing, issuer risk handling, and fallback or legacy magstripe processing. It also emphasizes that PIN data is never stored in Track 2 and is handled separately as an encrypted PIN block.

When a magstripe is successfully read, the terminal sends Track 2 (or its equivalent data) in the authorization request:

“track2”: “4761739001010119=25122011143804400000”

Track 2 is historically used for:

• Identifying the card (PAN + expiry)
• Routing via BIN tables
• Issuer card verification (CVV/PVV/iCVV)
• Supporting legacy magstripe transactions

The Decline of Magstripe — 2025 Reality

Magnetic stripe is now almost exclusively a fallback mechanism when chip (EMV) fails or is unavailable.

Key facts as of 2025:

Network Magstripe as Primary Magstripe Fallback Accepted? Liability Shift

Visa

No longer supported as primary in most regions

Only in extremely limited cases (e.g., damaged chip + merchant forced fallback) — increasingly rejected

Liability on merchant since 2015–2021 depending on region

Mastercard

Phasing out requirement

Still accepted as fallback in many markets until 2031–2033 (depending on country)

Liability shift completed in most regions

Amex / Discover / UPI

Similar trajectory — magstripe being eliminated

Fallback rarely accepted

Varies

→ In Europe, Australia, Canada, and most of Latin America and Asia-Pacific, pure magstripe transactions have been virtually extinct since 2018–2022. → In the United States, magstripe fallback is still relatively common due to slower EMV adoption, but even there it’s declining rapidly.

When fallback occurs, the transaction is flagged with specific indicators:

These fallback transactions usually trigger:

• Higher interchange fees
• Stricter velocity checks
• Increased fraud monitoring
• Potential decline by issuer

PIN Handling (Unchanged)

Track 2 contains only card data — never the PIN.

The PIN is captured separately and sent encrypted as a PIN block, e.g.:

“pin_block”: “1BE6AC1EE960FB890000000000000000”, “pin_ksn”: “FFFF9876543210E0000A”

Both fields remain independent in modern payment flows.

Bottom Line in 2025

• If you’re building a new POS or SoftPOS: always prefer EMV contact/contactless first
• Support magstripe only as a true fallback
• Be prepared for Visa to decline most magstripe-originated transactions in many countries
• Mastercard still allows fallback in more regions — but for how long?

Magstripe isn’t dead yet… but it’s on life support, and the plug will be pulled region-by-region over the next 5–8 years.

Originally published at https://corebaseit.com on November 25, 2025.