According to the EDPB guidelines on the concepts of controller and processor in the GDPR1, joint controllers are entities that jointly determine the purposes and means of the processing of personal data. Joint controllership can result from a common decision or from converging decisions that are necessary for the processing to take place. Joint controllers must have a transparent arrangement that sets out their respective roles and responsibilities, and must ensure that individuals can exercise their rights against each controller. In this scenario, Gellcoat and Freifish are joint controllers with respect to the personal data related to the event, because they both decided to share data from their client databases, to come up with a list of people to invite, to agree on the content of the invitations, and to build an app to gather feedback. These decisions are joint and inseparable, and they have a tangible impact on the determination of the purposes and means of the processing. However, Gellcoat and Freifish are separate controllers for their other purposes, such as maintaining their own client databases, marketing their own products, or complying with their own legal obligations. These purposes are independent and separate from the joint purpose of organizing the event. Therefore, option A is the correct answer. Option B is incorrect because joint controllership does not depend on the merging of databases or the ownership of data, but on the joint determination of purposes and means. Option C is incorrect because joint controllership does not require a written designation in a contract, but can be inferred from the factual circumstances. Option D is incorrect because separate controllers and processors have different roles and responsibilities under the GDPR, and Gellcoat and Freifish do not act as processors for each other. Reference:
Guidelines 07/2020 on the concepts of controller and processor in the GDPR What does it mean if you are joint controllers?
What's New in the EDPB's Draft Guidelines on Controllers and Processors under the GDPR