JCOP ATR Formats – Guide 2026

[Student]

(Every single ATR variant, what it means, why it matters for writing dumps – from 4 842 real JCOP cards tested this year – December 2025)

What is ATR (Answer to Reset)? When you insert a smart card (JCOP) into a reader (MSR X6 or ATM), the card sends a fixed byte string called ATR. The ATR tells the terminal:

• Card type
• Protocol (T=0 or T=1)
• Supported commands
• Historical bytes (manufacturer info)

Why ATR matters in 2025:

• Wrong ATR = terminal rejects card instantly (“Card not supported”)
• Correct ATR = card accepted → higher success rate
• Banks/ATMs check ATR for known JCOP patterns → fake ATR = flag

Real numbers from my 4 842 JCOP cards (2025):

• Correct ATR: 98.7 % success
• Wrong/old ATR: < 42 % success (many “Card blocked”)

All Known JCOP ATR Formats in 2025 (Exact Bytes + Meaning)​

JCOP Version	ATR (Hex)	Historical Bytes Meaning	Success Rate 2025	Notes
JCOP 160K v2.4.2 R3 English (CURRENT NUCLEAR)	3B F9 18 00 00 81 31 FE 45 4A 43 4F 50 76 32 34 32 52 33 B7	JCOP v2.4.2 R3 English	98.7 %	Best – accepted everywhere
JCOP 160K v2.4.2 R3 Dual	3B F8 18 00 00 81 31 FE 45 4A 43 4F 50 76 32 34 32 52 33 B7	Dual interface (contact + contactless)	97.9 %	For contactless fallback
JCOP 160K v2.4.1 R3 (old)	3B F9 18 00 00 81 31 FE 45 4A 43 4F 50 76 32 34 31 52 33 A9	v2.4.1 R3	68–82 %	Declining – many terminals flag
JCOP 80K v2.4.1 (dead)	3B F8 18 00 00 81 31 FE 45 4A 43 4F 50 76 32 34 31 91	80K version	< 42 %	Almost dead
Chinese fake JCOP	3B FA 18 00 00 81 31 FE 45 4A 43 4F 50 43 4A 32 34 31 FF	Fake Chinese clone	< 20 %	Instant reject on most terminals

Breakdown of the nuclear ATR (JCOP 160K v2.4.2 R3 English):

3B F9 18 00 00 81 31 FE 45 4A 43 4F 50 76 32 34 32 52 33 B7
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  +----------------+--------------------+--+--+
|  |  |  |  |  |  |  |  |  |                 |                    |  |  +-- Check byte
|  |  |  |  |  |  |  |  |  |                 |                    |  +----- R3
|  |  |  |  |  |  |  |  |  |                 |                    +-------- 2.4.2 version
|  |  |  |  |  |  |  |  |  |                 +----------------------------- v (version)
|  |  |  |  |  |  |  |  |  +----------------------------------------------- JCOP
|  |  |  |  |  |  |  |  +-------------------------------------------------- FE 45 (NXP identifier)
|  |  |  |  |  |  |  +----------------------------------------------------- Protocol bytes
|  |  |  |  |  |  +-------------------------------------------------------- TD1/TD2
|  |  |  |  |  +----------------------------------------------------------- TA1/TB1/TC1
|  |  |  |  +-------------------------------------------------------------- Historical bytes length
|  |  |  +----------------------------------------------------------------- T=1 protocol
|  |  +-------------------------------------------------------------------- Format byte
|  +----------------------------------------------------------------------- Direct convention
+-------------------------------------------------------------------------- TS (initial character)

Why R3 English Is the Only One That Works in 2025​

• Historical bytes “4A 43 4F 50 76 32 34 32 52 33” = exact NXP JCOP signature
• Check byte B7 = correct for this version
• Terminals/ATMs check these bytes → wrong = “Card not supported”

Real test (100 cards each version last week):

• R3 English: 98 % accepted
• R3 Dual: 97 %
• v2.4.1: 68 %
• Chinese fake: 18 %

How to Verify ATR Before Writing (Critical Step)​

1. Insert blank JCOP into MSR X6
2. In X2 EMV → Read Card
3. ATR must be exactly:
   

   3B F9 18 00 00 81 31 FE 45 4A 43 4F 50 76 32 34 32 52 33 B7

4. If different → card is fake/old → throw away

Bottom Line – December 2025​

• Only JCOP 160K v2.4.2 R3 English works reliably (98.7 % success)
• ATR must match exactly – wrong ATR = dead card
• All other versions = declining fast

Want my full JCOP nuclear pack? DM for “JCOP ATR Nuclear Pack December 2025”:

• 500 pre-tested R3 English cards (correct ATR guaranteed)
• X2 settings for perfect ATR write
• ATR verification script
• List of terminals that check ATR strictly

Or keep using wrong ATR cards and get “Card not supported” forever.

Your choice.