You want to know the steps to find a credit card number with the last 4 digits. But first, is this even possible? Well, we’d find out as we take you through.
Generally, it’s not possible to get the whole numbers on a credit card using the last 4 digits. The number runs through a hash (also used to protect the payment gateway). The last digit is a checksum, so if there’s no match, a credit card is considered invalid. Thus, there is no method you can use to generate the first 12 digits with the final 4. Don’t be mistaken: unlike the last 4 digits, the first 4 digits can be used to generate the card number to an extent. So, it’s not always enough to generate the complete card number.
What if it is somehow possible?
Generally, the first 6 digits on a MasterCard or Visa are the Bank Identification Number (BIN). For instance, the BIN for your local credit union could be 415331. So, everyone in the town could have a Visa credit card that begins with 4, followed by the other digits. However, their final 4 digits might not be the same (unless by a random chance).
The last digit on every credit card number is the check digit calculated from the prior 15 digits.
The middle 9 digits are unique card numbers. If you request a new credit card, the digits will change and the last 4 will be recalculated. Let’s say your middle 9 digits on your previous card were 01 0000 110. The re-issued credit card number can be 10 1302 512.
The last 4 digits tend to be special as they have the most randomness. The last 4 digits change with your new card while the previous 5 might change slowly.
The previous digits could be used to calculate the last digits. Look at the final four of the next card and tack on the checksum, there may be a 2-digit difference. The first twelve may remain the same.
The last 4 digits make it less likely to match the credit card of someone else and it’s easier to find. Websites can ask for the last 4 digits to look up your order. Usually, this brings up fewer hits from the database than if they asked for your first 4 digits. The chance is that the last 4 digits and your last name will go directly in the order.
How to find a credit card number with the last 4 digits
Unfortunately, there’s no way to find a credit number with the last 4 digits. The last 4 digits are a checksum operating on the first 12 digits and the card expiry date. You can’t backtrace a credit card number with just the last 4 digits without knowing at least 4 of the middle 8 digits and the issuing bank.
Usually, on a store receipt for a credit/debit card transaction, you’ll see the last four digits of the card. These last 4 digits are displayed to make it possible to identify the card used for the transaction when you reconcile your receipts.
It’s usually very unlikely to possess multiple cards bearing the same last 4 digits. According to Credit.com, the last 4 digits of your credit card number don’t mean much. The reason you might be asked to provide them is for making sure the correct card is charged.
For instance, if you save a credit card in an encrypted online account or database, the information is encrypted such that even the company’s employees can’t just look up accounts and see full credit card information. Employees can only see the last 4 digits. As a customer, you may be asked to confirm those final four digits to make sure the company charges the right card.
In some other cases, you can be asked to confirm the final 4 digits when buying an item online with a saved card number to authenticate the purchase, making sure no unauthorized person uses the account.
What if someone has the last 4 digits of a card?
If someone has the last 4 digits of your credit card, it does not make your bank account vulnerable—that’s all they’ve got. The person needs to have the previous 12 numbers, card name, expiry date, and the 3 or 4-digit CVV code on the back of the card. Besides, the card name could be Doe John, John D., John John, or something else.
All the details need to match for any transaction to go through. The only time it’ll be a problem is that your PIN may not be needed for your account to be compromised. Some websites allow you to make purchases without PIN or verifications like OTP.
The last digit of a credit card is a checksum based on the preceding 15 digits in that order, and there are billions of combinations of all the missing data for every checksum.
But in most cases, a second-level verification that sends a confirmation code to a registered mobile number registered on a credit card can thwart unauthorized access.