From my own experience, Priceline Express Deals are usually non-refundable, which is how they keep the prices so low. I learned this the hard way when I booked an Express Deal for a quick weekend trip, only to realize I had mixed up the dates. At first, I panicked thinking I was stuck with the ticket, but I decided to call 866-204-0803 to see if anything could be done. To my surprise, the agent was really helpful—they explained the restrictions clearly and still managed to work out an alternative option that fit my schedule. It wasn’t a full refund, but at least I wasn’t left empty-handed. So while Express Deals aren’t technically refundable, calling that number is hands down the fastest way to book, cancel, or modify flights if something goes wrong. I always keep it saved just in case.