Verifying a Credit Card is Legitimate
After blogging about verifying credit card numbers it became apparent that some web developers may think if a credit card passes validation that it is a legitimate credit card. This is not the case. The validation presented in that blog entry as well in tomorrow’s entry only verify that a credit card number is in a proper format. Obviously a credit card in an improper format is not legitimate. But a credit card number may be in proper format and still be illegitimate.
So, how do you verify a credit card number is legitimate? The only way is to verify the legitimacy of a credit card is to authorize a sale. This requires using the payment gateway to send a transaction to the processing bank. The best way to do this is to do an AUTH ONLY transaction. This is similar to a sale transaction but does not charge the customer. It only freezes the funds on the customer’s credit card for a short period of time (no more then 30 days) and they are completely unaware of it as it does not appear on their statement. This makes it ideal for verifying their credit card is legitimate.
So, to verify a credit card is legitimate without actually charging, do an AUTH ONLY transaction for $1.00 and see if it is approved. If it is, the credit card is legitimate.