Tips are not included in your Curb fare at the time of booking. Instead, Curb lets you set a predetermined default tipping amount. Your default tipping amount will be displayed next to the Curb fare before you book your trip. You should add these two prices together to calculate the total cost of your trip. Note that the tip is charged at the end of the trip, which will allow you to adjust it before the trip is over to account for the quality of service.