Track content of the magnetic stripe of the card

The first track of the magnetic stripe contains the information embossed on the card (PAN card number, card expiration date, cardholder name), as well as the card service code (service code), country code (for some categories of card numbers) and issuer special data (Issuer Discretionary Data). There is a check character at the end of the track.

The service code consists of three digits X, Y, Z.

The first digit (X) identifies the geography (intercountry and / or intracountry transactions are allowed) and the technology (magnetic stripe card, microprocessor card) of using the card. The first digit of the code is 1 and 5, indicating that a magnetic stripe card is being used for intercountry and intracountry transactions, respectively. Values 2 and 6 indicate the use of the chip card for intercountry and intracountry operations, respectively.

The second digit (Y) defines the issuer's requirements for the method of authorizing transactions performed on the card. Specifically, it determines whether online transaction authorization is mandatory by the card issuer. The digit Y takes the following meanings:

Y = 0 - there are no restrictions on the method of authorizing the transaction, in part

ness, the transaction can be served offline;

Y = 2 - the transaction must be authorized by the issuer in the mode

real time;

Y = 4 - the transaction must be authorized by the issuer in the mode

real time, except for cases stipulated in special bilateral agreements between individual servicing banks and the issuer.

The rest of the second digit is ISO reserved. The second digit defines the rules for processing a transaction only when using magnetic stripe technology.

The third digit (Z) defines the list of services available with this card, as well as the method for verifying the cardholder. Possible Z values for various combinations of service / verification method are given below:

Z = 0 - any service and mandatory verification of the cardholder by PIN (No restrictions and PIN Required); example - Maestro cards;

Z = 1 - any service and any method of cardholder verification (No restrictions); the most common value of the third digit in practice;

Z = 2 - only purchase of goods and services and any method of cardholder verification (Good and Services only (no cash));

Z = 3 - only cash withdrawal through an ATM and mandatory verification of the cardholder by PIN (ATM only and PIN required);

MasterCard

^? 9

Z = 4 - cash withdrawal only and any method of cardholder verification (Cash Only);

Z = 5 - only purchase of goods and services and mandatory verification of the cardholder by PIN (Good and Services only (no cash) and PIN required);

Z = 6 - any service and verification of the cardholder by PIN code, when possible (No restrictions and require PIN when feasible);

Z = 7 - only purchase of goods and services and verification of the cardholder by PIN code, when possible (Good and Services only (no cash) and require PIN when feasible).

The rest of the Z values are reserved by ISO. The third digit defines the rules for processing a transaction only when using a magnetic stripe (the chip card uses Application Interchange Profile, Application Usage Control, CVM List, Issuer Action Code, etc. data objects, which will be discussed in Chapter 3).

101 is the most common service code value for magnetic credit cards, 121 for Maestro magnetic cards.

Special data of the issuer, stored on the magnetic stripe of the card, determine:

• data used to protect card transactions (these include the CVC / CW values to ensure the integrity of the magnetic stripe data elements of the card, the PIN Offset value, sometimes used when calculating the cardholder PIN code using the IBM 3624 algorithm, or the VISA PW value when the issuer uses the same-name algorithm for generating / verifying the cardholder PIN-code);
• PAN sequence number - a number that allows you to attach several different cards to one PAN account;
• operational characteristics of the card used by the issuer when authorizing card transactions, for example, the date after which the card is no longer valid (expiration date).

The second track contains the same data as the first, except for the name of the cardholder. In the case of using a credit card, the name of the cardholder must be printed on the check of the POS terminal. Therefore, for credit products, either the first track or the first and second tracks of the magnetic stripe are personalized (to increase the reliability of reading information from the magnetic stripe), while for debit cards, as a rule, only the second, shorter track is personalized.

The third track of the magnetic stripe contains:

• PAN card number, country code (for some categories of card numbers), card validity period, card serial number;
• geographical use of the map (international map, intra-country map);
• type of account (current, savings, credit).

On the third track of the card, you can write two additional account numbers. If during the operation it turns out that there are not enough funds on the main account of the cardholder, the issuer checks the availability of the necessary funds on the additional accounts of the card.

Unlike the first and second tracks, data can be written to the third track during the execution of a transaction. This provides additional opportunities for controlling card expenses and ensuring the security of transactions.

For example, you can set the amount of funds that can be spent within a specified time interval and control their spending in the process of using the card. As a result, parameters such as the end date of the current time cycle, the value of the amount of money available to the cardholder until the end of the current cycle, the value ensuring the integrity of the data of the third track, and the signature of the track data changed during the operation can be recorded on the third track.

Finally, with the help of the third track, you can control the number of remaining attempts to enter the correct PIN-code, store the date of the last operation on the card. It should be noted that changing the parameters of the third track of the magnetic stripe by the card issuer is possible only in the association of banks that support additional fields in the interbank interface. For example, such changes cannot be made using standard interfaces of international payment systems.

The third track has not become widespread, and almost all modern POS terminals do not use it for data recording.

Yo OP, loving the deep dive into magstripe guts — it's like cracking open the old-school vault in an era where chips are king. Been grinding this scene since the early MSR days, from scraping tourist traps in Vegas to parsing bulk dumps from Eastern Euro skims. Your thread's timing is spot-on with the slow mag death rattle (more on that later). I'll supersize my last drop with hardcore encoding breakdowns, extended tool kits, real dump parsing examples, fraud vector evals, and some 2025-specific wrinkles. Newbies: Read slow, vets: Call out the BS.

If you're just dipping toes, remember — magstripes are plaintext dinosaurs. No crypto, just aligned magnetic domains begging to be slurped. But with EMV mandates biting harder, this knowledge's shifting from daily bread to niche relic. Let's dissect.

Magstripe Encoding: The Nitty-Gritty (Beyond ISO 7813 Basics)​

ISO 7813/7811 ain't just a spec — it's the blueprint for how bits flip to bucks. All tracks use Frequency/Double-Frequency (F2F) phase encoding: 0s are no flux reversal at clock pulse, 1s are a reversal mid-pulse. Clock's 210 bits per inch (bpi) for Tracks 1/3, 75 bpi for Track 2 (yeah, that low-res vibe lets it pack denser chars). Each "character" is 5 bits: 4 data + 1 odd parity (total 1s odd). Read least-significant bit first (LSB). Sentinels and LRC cap it — LRC is XOR of all bits (incl. parity) from start to end; valid if 0.

• Track 1 (IATA Spec, Alphanumeric Beast): 79 chars max, 7-bit words (6 data + parity). Data's ASCII-minus-32 (e.g., 'A'=65-32=33, binary 100001). Starts %B (hex 25 42), PAN in BCD (every 2 digits = 1 byte), ^ (3E) seps, name (left-just, / for spaces, up to 26 chars + 2 fillers), ^, exp YYMM (BCD), service code (3 BCD digits), disc data (CVV1 here sometimes, 3-13 digits), ends ? (3F) + LRC. Why alpha? Airline ticketing legacy — names for manifests.
  Example raw dump (post-decode):
  
  Code:

  %B4111111111111111^DOE/JOHN A ^25051011000000000000?;

  Breakdown: PAN=4111111111111111 (test Visa), Name=DOE/JOHN A (spaces as /), Exp=25/05, SC=110 (intl auth, chip req, no restrictions), DD=000... (padded).
• Track 2 (ABA Spec, Numeric Workhorse): 40 chars max, 5-bit BCD (4 data + parity). Simpler: ; (3B start), PAN, = (3D sep), exp YYMM, SC, DD (CVV2 offset often), ? + LRC. No names — keeps it lean for ATMs/POS. DD can hide PIN verification values (PVV) or impact codes.
  Example:
  
  Code:

  ;4111111111111111=25051011000000000000?;

  Parse tip: PAN ends at first non-digit after 13-19 digits. SC decode: 1st digit (1=intl, 2=intl chip, 5=natl, 7=natl chip), 2nd (0=no PIN, 1=offline PIN, 2=sig, etc.), 3rd (0=normal, 1=low value, 6=manual).
• Track 3 (Financial Thrift, Numeric Monster): 107 chars max, same 5-bit BCD as Track 2, but 210 bpi. Starts + (2B? Wait, actually < hex 3C for some), packs account subnums, cycle counts, PIN try counters, discretionary for banks (e.g., 101 chars fixed + 6 DD). Rarely on consumer cards — mostly ATM/intra-bank. Juicy for offset calcs if you're into PIN cracking (e.g., VISA PVV = f(PAN digits + service + exp + track3 offset)).

Pro move: Always validate LRC in code. Bad parity? Reswipe or flag as tampered. And coercivity matters — HiCo (4000 Oe) holds vs. LoCo (300 Oe) for cheap badges. Readers detect via signal strength.

Tools & Methods: Full Arsenal (2025 Edition)​

Hardware's commoditized, but software's where the magic (and malware) hides. With mags fading (US issuers dropping 'em post-2027 per Mastercard), focus on hybrids with NFC/EMV sniffers. My updated stack:

1. Entry-Level Hardware: MSR605X/MSP808 Clones ($15-60, Ali/Tor Markets)
   • Bi-dir read/write, EMV passthrough. Outputs ISO format or raw hex via USB-HID (keyboard mode).
   • Setup: VCOM drivers on Win11 (bypass UAC with admin), or Linux msr-tools. Batch mode: Swipe 10x, average signals to beat jitter.
   • 2025 Twist: Firmware hacks for BLE add-on (cheap ESP32 mod). Example output parse in Bash:
     
     Bash:

     #!/bin/bash
     msr -t1 -t2 | grep -oP '%B\K\d{13,19}'  # Pull PAN from Track1

   • Con: Fake clones brick easy — buy from vetted DNM vendors.
2. Software Powerhouses: LibreMSR + Custom Parsers (Free, GitHub Dark Forks)
   • LibreMSR (Python lib) for serial dumps: Handles F2F decode from raw waveforms.
     
     Python:

     from librem sr import MSRReader
     reader = MSRReader(port='COM4')
     tracks = reader.read_card()
     if tracks['lrc_valid']:
         pan = re.search(r'%B(\d{13,19})', tracks['t1']).group(1)
         print(f"LIVE BIN? {pan[:6]}")  # Check binlist db

   • Pair with BinDB scrapers (Tor .onion sites) for issuer intel. I've scripted it to auto-flag Amex (37xx) vs. MC (51-55xx).
   • Alt: MMSTRC16 v2.1 — old DOS relic, but emulates perfect in DOSBox. Logs bitstreams for forensic replay.
3. Pro/Stealth Rigs: Omnikey 5022 + ACR39U (NFC/Mag Hybrid, $80-150)
   • USB CCID for EMV, mag head for stripe. Apps like "Stripes" (APK sideload) stream to Telegram bots.
   • 2025 Hack: Integrate with Kali's magstripe module for live CVV gen (using DD offsets). Stealth: Headless mode via Raspberry Pi Zero W — mount in a fake wallet.
   • Pitfall: EU regs (PSD3) flag mag-only txns; test on fallback-enabled terminals.
4. DIY Forensics: Pi + ADALM2000 Scope ($100 Build)
   • Hall-effect sensor or salvaged head, capture analog signals at 1kHz. Decode with PyF2F lib (F2F sim).
   • Use case: Spot re-encodes — legit stripes have uniform flux; fakes jitter at edges. I've ID'd 20% bad dumps this way from bulk lots.
5. Bulk/Cloud Tools: AWS Lambda Parsers or Dark Pool Bots ($/mo Subs)
   • Upload .bin dumps to anon S3, parse via serverless — outputs JSON with risk scores (e.g., exp <6mo = high value).

Pitfalls, Vectors & 2025 Realities​

• Tech Traps: Bit slip from dirt/head wear — manifests as parity fails (odd #1s). Fix: Clean with iso alcohol, or software debias (majority vote on 3 reads). Double-density misreads kill Track 2 (its 75 bpi tricks high-speed heads).
• Fraud Evasion: Banks (Chase, Citi) geofence mag swipes — US-only post-2023. Service code '2xx' forces chip, so stripe clones flop on new POS. CVV on stripe? Volatile; gen2 uses dynamic ARQC.
• Decline Wave: Mags are ghosts now — 80% US cards chip-only by Q3 2025, per Visa stats. Early 2030s full sunset, but legacy ATMs/gift cards keep 'em viable in LatAm/Asia. Shift to shimmers (mag+chip skim) or contactless sniffers.
• OpSec Gold: Never test live — use Square sims or cloned test bins (4111...). Logs show stripe vs. chip; mix 'em for blend-in. And quantum? Nah, but AI anomaly detection (e.g., Stripe's ML) flags odd PAN patterns.

My Latest Grind & Thread Fuel​

Q2 2025 haul: 200 dumps from a FL gas skim — 65% Track 2 only, 12% with Track 3 PVVs (cracked 3 PINs via VISA algo sim). Filtered via Python bin checker: 28% live, avg $2k limit. Sample anonymized CSV snippet:

Shared full parser script.

OP, you chasing stripe revival hacks or EMV bridges? Specific pain: Encoding a full Track 1 name with accents? (Use / for é, but it mangles.) Thread fam: Who's got 2025-compliant writers for HiCo3 cards? Or best shimmer blueprints? Spill — let's evolve this before mags ghost for good.

Stay shadowed, don't get pinched.