LeeParts.com takes credit card fraud very seriously. To protect us and our customers we use VeriSign Payment services for all of our credit card transcations. In order for your transaction to be approved, you must enter the correct billing address that your credit card company/bank has on file, your correct credit card number, expiration date and you must enter the correct CSC number. This number can be found on the back of your card, in the signature line. It is the last three numbers. Some American Express cards have four numbers on the front of the card. Please contact us if you have additional questions or believe your credit card was declined in error.