A ticketing method for issuing a service ticket of a transport system to a passenger comprises: checking-in the passenger via a mobile device of the passenger upon accessing a vehicle of the transport system; checking-out the passenger via the mobile device upon exiting a vehicle of the transport system; and a server computer automatically calculating a price for a travel of the passenger within the transport system by evaluating check-in data representing the checking-in of the passenger and check-out data representing the checking-out of the passenger. The ticketing method further comprises: a sensor of the mobile device of the passenger generating a sensor data signal; transferring the sensor data signal from the mobile device of the passenger to the server computer; the server computer automatically calculating a travel movement pattern dataset based on sensor data associated to the transferred sensor data signal; the server computer automatically, comparing the travel movement pattern dataset to a transport system movement pattern dataset; the server computer automatically identifying a non-compliance of the travel movement pattern dataset with regard to the transport system movement pattern dataset; and the server computer generating the check-out data using the identified non-compliance. The method according to the invention allows for conveniently, efficiently and reliably issuing tickets for travelling with public transport systems.