You sure can.
To change your card details, you'll need to remove the old card and add a new card.
** You need to go through to the payment page and pretend you're going to make a payment in order to access the vault which stores your card details
Removing a card:
Once on the Payment Page, select the card you wish to remove/edit and click Remove Payment Method
Adding a card:
To add a card to the payment page, click on the generic card logo, enter the details and confirm payment. Once you confirm payment, the new card details will be stored automatically for your next purchase
Please bear in mind that Everything5pounds.com does not store any payment details on our website. Any card details displayed are only visible to you and are stored on an encrypted network by the secure payment verification system, powered by Safecharge.
Whenever shopping on any online website or viewing online banking statements, it is important to remember that any details provided on a webpage which starts with HTTPS are sent via an encrypted and secure network.