Creating supply in public transport is typically based on demand data which is a fundamental prerequisite. However, reliable and publicly available information are often difficult to access or very limited, which is especially the case for the night train market. Taking advantage of NUTS classification by Eurostat is therefore being tested as it provides publicly available, standardized and comparable data for most parts of Europe. To evaluate the usability of this data for supply planning of overnight trains, this approach is tested for the observation area of Portugal, Spain and France by creating overnight routes and comparing them with actual train services in 2021 timetable. The results verify to examine the idea in more detail and to extend the approach for further research.