The paper acts as a guide for UK data custodians and other organisations involved in data sharing and information governance both within and beyond the health sectors. It identifies and provides principles, approaches and guidelines for data sharing and linkage practice within TREs, as well as examples of best practices drawn from the experiences of colleagues working in the Alliance and internationally. The guidelines and principles in the paper are structured around the ���Five Safes��� framework for the access of health data ��� safe people, safe projects, safe settings, safe data, safe outputs. The White Paper also sets out principles for the federation of Trusted Research Environments - how they can be linked, to substantially enhance the scale of secure and trustworthy data linkage and research.