The majority of airlines (except Flybe, Adria Airways, Aegean Airlines, Aeroflot, Blue Express/Blue Panorama Airlines) give the customer up to midnight on the day they have booked to cancel without charge. Other airlines, such as Scandinavian Airlines, Tap, Lufthansa, Swiss International, Austrian Airlines, Brussels Airlines and United Airlines, give you a larger window to cancel without charge, either up to 24 hours after booking or up to midnight on the following day. The latter, however, may implicate a fee.