The 24-hour flight cancellation policy can be a powerful tool for travelers, especially when it comes to booking cheap flights. Say you get an alert about a great flight deal from Thrifty Traveler Premium, but aren't sure if the dates will work or if you'll have time. Don't wait: Book a flight to lock in a cheap price, then use the next 24 hours to figure out the logistics and decide if you want to make the trip. LOT Polish Cancellation Policy says if you change your mind, the airline must give you a full refund, as long as you cancel within the 24-hour window.