User perceptions of service quality are essential to promote public transport ridership and trigger positive externalities. Therefore, research efforts need to analyze service quality from the point of view of users. This article builds on the stream of works studying perceptions of public transport service quality but shifts the focus towards user heterogeneity. Using a discrete choice experiment this article attempts to disentangle different dimensions of decision heterogeneity for bus services. Among the main findings the article discusses the implications of different types of decision heterogeneity, such as non-linear preferences, and relates this to the formulation of bus service contracts.