As a matter of good security practise, we do not retain any card details on

During checkout, card details are immediately and securely passed to our online payment partner, and then removed from our system.

While this means that you have to enter your card details every time you complete checkout, it is more secure. For example, if you gave your computer to a third party, they might be able to use your account to make purchases, if your card details were stored on any website, for which you had an account on your computer..