Accountability has emerged as a critical concept related to data protection in cloud ecosystems. It is necessary to maintain chains of accountability across cloud ecosystems. This is to enhance the confidence in the trust that cloud actors have while operating in the cloud. This paper is concerned with accountability in the cloud. It presents a conceptual model, consisting of attributes, practices and mechanisms for accountability in the cloud. The proposed model allows us to explain, in terms of accountability attributes, cloud-mediated interactions between actors. This forms the basis for characterizing accountability relationships between cloud actors, and hence chains of accountability in cloud ecosystems.