The General Data Protection Regulation (GDPR) will affect (with very limited exceptions) all those who control or process data relating to a living individual, through which that individual could be identified. This will, therefore, include trustees (and other trust professionals) and their advisers, who hold and process information about beneficiaries of trusts and, potentially, other people connected with them. The data controller is the natural or legal person, or body that determines the purposes and means of the processing of personal data. Trustees or their advisers may be the controller, either alone or jointly with others. Processing means any