You can cancel a Carnival Cruise without penalty only if you do so within 24 hours of booking and the sailing is at least 76 days away. After that, Carnival cruise cancellation fees apply based on how close it is to your departure date. To cancel a Carnival Cruise, log into your account and follow the steps under your booking, or use the cancel Carnival Cruise online option if availab... https://www.cruisesfares.com/blogs/carnival-cruises-cancellation-policy