Contactless mobile payment devices are fast, convenient and user friendly means for executing small value business transactions. This kind of transactions is preferred to be executed conveniently and on the fly by just tapping a mobile payment device to a mobile terminal. Mobility, convenience and fast transaction execution are very important payment system properties in potentially crowded places such as in public transportation. These properties are in practice causing transaction execution problems, such as: delays in offline transaction execution, transaction atomicity failures caused by mobile data communication drops, lack of central control on mobile transaction system components and increased vulnerability risk caused by easy physical access to the mobile transaction system components. This paper describes a holistic transaction processing model for resolving mentioned problems in micropayment mobile touch-and-go transaction systems. Defined processing model was implemented on real public transportation mobile payment system where it was proven as a robust solution for execution of small value touch-and-go mobile ticketing transactions.