If you have an Uber Cash balance in your account, it can be used automatically to pay for your trips and cancellation fees. You can always see the Uber Cash balance available in your account by choosing "Wallet" from the menu.
If you want to toggle on your Uber Cash:
1) Enter your destination on the home screen
2) Press on "Payment" below the car selection
3) Turn on your Uber Cash
Please note that you cannot switch the payment method after requesting the ride. If you would like to switch the payment method, press on "Help" in your app to inform us. We will be happy to change it for you.
If you don't have enough Uber Cash to cover the cost of the ride, you will be given the option to purchase the remaining amount to pay for your trip, or your pay the rest of the fare by your default payment method.