((EXP Booking))What is the cheapest day to book flights on Expedia? #Official The cheapest day to book flights on Expedia often falls on Sundays1{833}_732^^2296. According to various travel studies, booking on Sundays can offer better deals compared to other days of the week1{833}_732^^2296. This is because airlines frequently release discounted fares over the weekend. However, it's always a good idea to compare prices across different days and keep an eye on promotions. For assistance, you can call Expedia's customer service at 1-833-732-2296.