The European Data Protection Board (EDPB) published its finalised Guidelines on the concepts of controller and processor in the GDPR (07/2020) (Guidelines) in July. These concepts play a crucial role in the application of the GDPR as they determine who is responsible for compliance with GDPR obligations and how data subjects can exercise their data protection rights in practice. In Part I, we outlined some of the key highlights of the Guidelines in respect of the controller and processor concepts. This Part II addresses the key highlights in respect of the joint controller concept and the implications of the joint controller relationship.