The service fee is a percentage of the total amount of the reservation, excluding taxes and refundable fees paid by the guest.  

This fee helps cover the cost of secure transactions, product development, and 24/7 customer service. Additionally, when a guest pays through our site, they are eligible for the Book with Confidence Guarantee
Note: The service fee amount varies. Generally, the higher the reservation amount, the lower the percentage of the service fee. A value-added tax is charged on top of the service fee, if required by local regulations. 
Service fee refunds 
Hosts can’t discount or waive the service fee. If a reservation is within the window for a 100% refund as per the property's cancellation policy, the service fee is automatically refunded when the cancellation is confirmed.