Sometimes, your customer might enter a cancelled, non-issued or invalid card number in the Payment Form. This payment information is validated on the backend when processing the payment.
Card numbers are validated by:
Getting the card token.
Using card number field values, excluding non-numeric characters.
Passing the remaining digits through the Luhn algorithm.
Passing the remaining digits of the credit card through the Luhn algorithm does not prove the validation but helps prevent typing errors.
