A common form of handling credit card transactions, online or offline is to establish your website using a standard merchant account with your card company or bank.

Having this authorization allows your business to take card payments physically and online. With this option you can take payment in various forms yet have standard control.

The main disadavantages are that the merchant rate you pay for every sales is high (usually between 4-5%) unless volumes justify a preferred rate) and there may be considerable custom programming required to carefully integrate with the payment system. Also, procssing different cards may require different procedures and agreements set up with each card vendor.