The most important part in accepting a credit card online is to verify the cardholder is actually placing the charge.

On the Internet, this can be done with Address Verification System.

What is the Address Verification System (AVS)?

The Address Verification System (AVS) is an advanced level of credit card security that is now used to help guard against credit card fraud. When a card is sent to the bank for processing the house number portion of the address and postal code entered with the order must match that of the cardholder on file. This is another way to ensure that the owner of the card is in fact the one using it. If the address does not match then the transaction is declined and sent back to merchant. At that point the merchant has to decide whether to process the transaction anyway or reject it. If the merchant chooses to process the card (even though it’s address is invalid) they pay a higher transaction fee. This is called an unqualified transaction. A transaction with an address that verifies is said to be qualified and the merchant is charged their normal transaction fee.

See also…

Internet Law Forum

Online Purchases and Sales