If you receive this error at the time of payment, it is because the card number being entered is invalid.
Luhn compatible or MOD 10 errors result from an incorrect card number being entered. Credit cards use something called a check sum algorithm that validates the that the credit card number is legit. The algorithm was created by IBM scientist Hans Peter Luhn who filed for a patent on the formula in 1954 and is used to verify credit card numbers, IMEI numbers, Social Security numbers and more. The formula helps identify if numbers are mistyped by applying a series of math steps to the number that have a defined outcome (the check digit).
Want to learn more about Hans Peter Luhn?
Please verify the full card number and details with the customer and try again.