Unless there has been a change I have forgotten about then the answer is that you can accept a limited number of credit card payments using a personal account. When a card payment is made you receive a message to say you have a pending payment and you have to log into ebay to accept it, onc e you have reached the limit, 3 I think, then you will be told you have to upgrade to accept the payment.

If you are a seller you really should upgrade before you start so that you have seller protection against spurious claims.