In order to accept credit cards directly, you will need a merchant account, and access to 1 of our supported payment gateways. You will then need to enable each credit card that you want to accept in the Payment Methods table, and enable your Payment Gateway. There are alternatives to having a merchant account that allow your customers to pay you via another company's website. 2 of these that are supported by Squirrelcart are PayPal and 2Checkout.