Cancelling an Uber ride as a passenger does not negatively impact your numeric rider rating. Ratings are based solely on the feedback left by drivers after a completed trip. Since a cancelled trip never officially ends with a rating screen for either party, the driver cannot give you a "1-star" for cancelling. However, there are other consequences: if you cancel more than two minutes after being matched (or five minutes for premium rides), you will be charged a cancellation fee to compensate the driver for their time. Furthermore, if the Uber algorithm detects that you are "mass cancelling" multiple rides in a row in a short period (perhaps to "fish" for a specific driver or car type), the app may temporarily block your ability to request a ride for 20 to 30 minutes. While your "star rating" remains safe, your wallet and your access to the service may be affected by frequent cancellations.