The aim of the Open Mobile Ticketing Alliance is to enable the vision of ‘Register once, travel anywhere’ by developing open, interoperable standards with payment vendors and transit operators.The overall objective of the OMTA is to define and promote an open, standards-based solution for mobile ticketing, based on an alternative and open mobile ticketing solution. The Open Mobile Ticketing Alliance builds on top of open payment systems, replacing cards with a mobile device. This device (usually a mobile phone) is used as an identifier to gain access to the public transport system. All transit system data and business logic, as well as the passenger’s payment information, is stored in the cloud, enabling a truly interoperable open payments-based ticketing system. Passengers register for the service only once and can travel in all public transport systems that support the solution without further registration or set-up. When entering a public transport vehicle, Passengers present their Phones to a Validation Device, authorizing that Journey. The Phone would communicate the Passenger’s identifier securely to the Validation Device through the proximity radio interface (NFC) or, in the future, via another communications channel such as Bluetooth. Through a series of secure interactions, a Tap Record is created that uniquely links the Passenger’s Phone to the Validation Device at that time. This Tap Record is uploaded to the cloud, where fare calculation and life cycle management, including all financial transactions, are centralized.