Expedia’s cancellation policy varies based on the type of booking. For flights, you can cancel within 24 hours of booking for a full refund, if the flight is at least 7 days away. Hotel and car rental policies differ, with some offering free cancellations and others charging fees or penalties.
Source: https://bcpportal.bcpcouncil.gov.uk/forums/general-discussion/b0ab29cb-dd9d-ef11-95f5-6045bd11e914