How can I get the credit card service code?

I'm new to this topic and I found it very interesting how all the payment system is currently working. To be honest it looks like they are not doing enough to stop fraudulent activity with Credit Cards.


From my understanding, each card has a smart chip that uses encrypted data, this to overcome the Magstripe plaintext.


The problem is that each card STILL has a Magstripe in case EMV is not working(Merchant don't wanna lose customers).


When the POS cant read the Chip, it will fallback to the Magstripe. What criminals are doing is cloning track 1//2 on Mag cards with blank/unreadable Chip, this will cause the POS to fallback to Magstripe transaction... and the whole EMV is irrelevant in this case.


I thought this is extremely dangerous and went to the wild to check it on my own card(201 / Chip and Pin) and here is the outcome:


I cloned my own CC (201 / chip) on a blank Magstripe card and went to the ATM.. after typing the PIN i got the withdrawal screen, pressed on the lowest amount then the ATM said "Service is Unavailable for this card".


I know that when changing the service code, the CVV1 is also changed (DES encryption of PAN, Exp Date and Service code = CVV1). But I changed it to see what will happen.


It's so weird, The cloned card of my own CC worked just on 1 model of ATM. I even tried to change the CVV1 to a random number and it's still working on that specific ATM(My bank is not even checking CVV1 ????)


Does anyone know what's going on? Why when changing the Service Code is it working on 1 Model of ATMS? Why is my bank not verifying the CVV1 value?


Can someone please explain why my own cloned card is not working when using 201 as service code? The POS should do a fallback transaction as he cant read the Chip.


It's really confusing and scary at the same time, how this simple trick (Changing 201 to 101), made the POS to continue the transaction, and then the bank didn't even verify the CVV1(I even typed 000 then random number and still it works).

Should I report this to my bank/POS company?

After hours of research about the credit card service code, I think I found the answer: This specific ATM model (Private company) doesn't have the authorization to transfer track data in the request message, therefore CVV1 is not checked by the bank! https://stackoverflow.com/questions/29820337/difference-between-pos-entry-modes-field-22#34044458 " '90' used in case track data present in the ISO 8583 request message, '02' - if, for the same reason, the acquirer or terminal device is not qualified to transfer track data in the request messages." @iso8583.info-support

So the POS entry mode for this ATM Model is '02', that's why no matter what CVV1 value I encoded in the track data, the withdrawal was successful. Is that something normal or should I report it? How criminals are still doing ATM frauds with cloned cards? In Europe, all ATM fallback transactions must be declined according to This : pg 226 - 7.6 https://www.mastercard.us/content/dam/mccom/global/documents/transaction-processing-rules.pdf



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Answers (2)

The credit card service code is a three-digit number embedded in the magnetic stripe of a credit card. It indicates where the card can be used and whether additional security measures (like PIN verification) are required. Here’s how you can retrieve it:

1. Read the Magnetic Stripe

The service code is stored in Track 1 and Track 2 of the card’s magnetic stripe.

To extract it, you need a magnetic stripe reader (MSR).

When swiped, the reader provides encoded card data like this:

  B1234567890123456^CARDHOLDER/JOHN^2405121000000000000000777000000

Here, 777 is the service code.

2. Locate the Service Code in Track Data

The service code is usually in positions 14-16 of Track 2 data.

Example Track 2 format:

  1234567890123456=24051210000077700000

The 777 in the middle is the service code.

3. Decode the Service Code Meaning

The first digit indicates authorization type:

2 – International use with a chip

5 – International use, magnetic stripe only

The second digit defines authorization processing:

0 – No restrictions

2 – Must be used with a PIN

The third digit specifies usage conditions:

0 – Normal

1 – ATMs only

2 – No cash access

4. Important Security Considerations

Only authorized payment processors should access service codes.

Storing or handling Track 2 data is prohibited under PCI DSS compliance.

Retrieving the credit card service code requires a magstripe reader, but be mindful of security regulations when handling card data!

1 Month

The service code on a credit card, also known as the "CVV" or "CVC," is a security feature designed to help verify that the card is in the possession of the cardholder during card-not-present transactions (e.g., online or over the phone). Here's how you can find the service code:


Physical Credit Card: The service code is typically a three- or four-digit number printed on the front or back of your credit card, depending on the card network.

Visa, Mastercard, and Discover: The service code is usually a three-digit number printed on the signature panel on the back of the card.

American Express: For American Express cards, the four-digit service code is printed on the front of the card, usually above the card number.

Digital Wallets: If you're using a digital wallet or payment app, such as Apple Pay, Google Pay, or Samsung Pay, the service code is not explicitly provided to you. These platforms use tokenization to generate a unique digital card number for each transaction, which is not the same as the physical card's service code.

Online Account: Some credit card issuers provide access to your credit card details, including the service code, through their online banking portals or mobile apps. Log in to your account and navigate to your credit card details to find this information.

Contact Issuer: If you're unable to locate the service code on your physical card or through your online account, you can contact your credit card issuer's customer service for assistance. They should be able to provide you with the necessary information.

It's important to keep your credit card information secure and not share your service code with anyone who doesn't have a legitimate need for it. Additionally, never provide your service code in response to unsolicited requests, as it could be a phishing attempt.


11 Months

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