The aim of this paper is to provide one uniform representation of functional concepts for the whole field of financial infrastructures. This encompasses the part of the infrastructure with inherent systemic risk such as financial market infrastructures but also retail payments including new instruments such as mobile payments and new phenomena like Bitcoin. The framework consists of three domains: settlement risk exposures, the value space and information messages. It also contains three types of agents and three types of links. The framework is used to describe the settlement problem (ie, how to reduce settlement risk exposures) and its general solution (sending structured messages in the information domain in order to induce changes in the value space). Its uniform structure allows for the analysis of settlement risk exposures across the different layers of the financial infrastructure of an economy. As such it is possible to study the properties of different, alternative solutions to the settlement problem in practice. It is shown on the basis of a number of examples that the framework is capable of representing basic notions of payment and securities settlement systems.