A great number of mobile payment schemes exist in the market. This paper suggests a framework, based on payment type and technology, to classify mobile payment schemes. The framework supports a definition of mobile payments as a way to use existing payment instruments. Based on the framework, mobile payments' success factors from the payer and payee viewpoints are discussed. In the mobile payments value chain, both banks and mobile operators are critical players, but their business cases are not self-evident. This paper aims at contributing to central banks' need to better understand the functioning of mobile payment schemes and mobile payment markets.