The Handbook of cross-border data exchange is part of the project ‘World’s smoothest cross-border mobility and daily life through digitalisation’, with a broader objective of streamlining the daily life and mobility of citizens and companies across borders by facilitating the exchange of data between authorities in the Nordic and Baltic countries. The handbook is collects the lessons learned in cross-border data exchange in the fields of studying and using healthservices in another Nordic and Baltic country, and in the use of Nordic and Baltic legal databases. The aim is to provide the reader with insights and ideas for future development by pinpointing identified networks, interesting initiatives, and potential funding mechanisms, as well as highlighting case examples that could be utilised in the development of cross-border collaboration.