All valid MasterCard credit and debit cards display a set of unique features that every merchant should be familiar with. Every time you accept a MasterCard card for payment, while waiting for the authorization response, you should scan these features and make sure that they have not been altered or tampered with.
I will review these card identification features below and will explain how to verify their validity. Additionally, I will review the MasterCard number format and, for e-commerce merchants, I will show you how to validate the 16-digit account number of every MasterCard credit or debit card that is presented for payment on your website. You can build your own program to utilize this technique or just buy one that is already available, but either way it is a great way to authenticate card numbers.
MasterCard Number Format
Each card number, whether belonging to MasterCard or to some other payments company, begins with an issuer identification number (IIN), which is always six-digit long. As its name implies, the IIN is used to identify the card issuer who is issuing its cards through a card network (e.g. MasterCard or Visa). In our hypothetical example illustrated in the image to the right, the card’s IIN is “529964”.
IIN ranges are allocated to the issuing networks by the American National Standards Institute (ANSI) and the networks then allocate them to their card issuers. The table below lists the IIN ranges for MasterCard and Maestro, which is a debit card service owned by MasterCard and big in Europe.
So all MasterCard debit and credit card numbers start with 50, 51, 52, 53, 54 or 55 and are 16-digit long. The numbers are spaced in four groups of four digits each, like this: “5xxx xxxx xxxx xxxx”. Furthermore, as I have explained below, each MasterCard and Maestro card number can be easily validated using a simple algorithm.
MasterCard Card Identification Features
Here are the MasterCard identification features you should be examining:
- All cards must include a full-color MasterCard brand mark.
- MasterCard account numbers must always start with the number “5.”
- The first four digits of the card number must be the same as those printed directly below (pre-printed BIN).
- The 16-digit card number must be clear and uniform in size and spacing and must appear on one line.
- The expiration date should be in the future and in the format “mm/yy.”
- There may be a chip on some cards, located above the account number.
- The MasterCard Hologram or HoloMag tape can be located on the front or back of the card. If located on the front, it will be above the brand mark. If located on the back, it will be next to or below the signature panel.
- On some cards, the design and brand mark may be oriented vertically.
- The signature panel is located on the back of the cards, with the word “MasterCard” printed in multi-colors at a 45?? angle.
- The last four digits of the account number must be printed in reverse italic letters on the signature panel.
- The Card Verification Code 2 (CVC 2) must be printed in reverse italics to the right of the last four digits of the account number within the signature panel.
- The magnetic stripe must be present, located above the signature panel and appear smooth and straight with no signs of tampering. On some cards the HoloMag tape may be used in place of the magnetic stripe.
Here is the current MasterCard design, first the front of the cards:
And here is the back of the cards:
There are different MasterCard designs in use today and some of the above identification features will not be present on some of the cards you accept. However, all security features that are present must comply with the above specifications.
How to Validate MasterCard Numbers
Now, as promised, I will show you how to verify that a MasterCard number is a real one. It is a simple technique that is especially useful in e-commerce transactions, where, while you don’t have the luxury of physically inspecting the card itself, you do have the time to validate its account number. You can design your own program that does it for you or simply buy one that is already available.
The technique for validating MasterCard, and most other credit card numbers, uses the Luhn formula (also called the Luhn algorithm or the “mod 10” or “modulus 10” algorithm). It is a straightforward procedure, which authenticates a card number in the following three-step process:
- Begin by doubling the value of every odd digit of the card number you are verifying. If the resulting sum of any given doubling operation is greater than 9 (for example, 7 x 2 = 14 or 9 x 2 = 18), then add the digits of that sum (e.g., 14: 1 + 4 = 5 or 18: 1 + 8 = 9).
- Now add up all the resulting digits, including the even digits, which you did not multiply by two.
- If the total you received ends in 0, the card number is valid according to the Luhn algorithm; otherwise it is not valid.
Now let’s put the Luhn formula to work and inspect this MasterCard number: “5511242466117883”. Here is what we get when we follow the three-step process I’ve just outlined:
The end result — 60 — ends in 0, which means that our MasterCard number passes the Luhn algorithm test and is valid. Of course, the fact that a card number is valid does not eliminate the possibility that something else may be wrong and the card may still be counterfeit, so you will need to follow best card acceptance practices. We’ve already examined MasterCard’s security features, so you should be well prepared to identify a card that has been tampered with. Now let’s see what you should do if you come across such a card.
What to Do if You Suspect Fraud
If your examination of the card’s identification features leads you to believe that the card has been altered in some way or is counterfeit, you will need to make a Code 10 call to your processor’s authorization center, which alerts the issuer to suspicious activity.
Once you are connected, just say “I need to make a code 10 authorizations request” and answer the operator’s questions with a simple “yes” or “no”. Remain calm and speak in your normal voice, so that to avoid alarming your customer.
Once the operator has collected the information he or she needs, they will instruct you how to proceed with the transaction. If it is necessary to call the police, the operator will do so. You may be instructed to retain the card, which you should only do if it is safe.
The ability to physically inspect the card presented for payment and to evaluate the behavior of the customer is what sets face-to-face transactions apart from non-face-to-face ones. It is also what makes them less expensive to process. There is no excuse not to benefit from your advantage.
Examining the identification features of a MasterCard card should only take a well-trained person a couple of seconds, which is about how long it takes to receive the authorization response. There is no better way to use this time and you should make it a routine part of the card acceptance process.
Image credit: Flickr / Hakan Dahlstrom.