The ongoing diffusion of novel and mobile devices offers new ways to provide services across a growing set of network technologies. As a consequence, traditional information systems evolve to multichannel systems in which services are provided through different channels, being a channel the abstraction of a device and a network. This work proposes a quality model suitable for capturing and reasoning about quality aspects of multichannel information systems. In particular, the model enables a clear separation of modeling aspects of services, networks, and devices. Further, it embeds rules enabling the evaluation of end-to-end quality, which can be used to select services according to the actual quality perceived by users.