From a tablet, PC or Lap-Top :-
On the search results page (where the available car photos are displayed), scroll down the left-hand side menu at the bottom you may see a tick box, to filter out suppliers who do not accept Debit.
From a mobile:-
On the search results page (where the available car photos are displayed), at the top of the page you see a blue “ Filter “ button, click on it and a choice of filters is shown. Click on the filter option “ Cards accepted at pick-up “ (if available), click “ Both Credit and Debit Cards “, click “ Done “, finally click “ Apply “ to filter out suppliers who do not accept Debit.