Industry is facing growing pressure to reduce greenhouse gas (GHG) emissions and waste by regulation. Circular economy principles can be used to optimize resource flows in industry. However, industry still faces concrete financial, regulatory, technological, and organizational barriers to do so. For the establishment of industrial synergies, ecosystems can be seen as a useful concept to frame and implement circular economy principles. New digital tools can support the implementation of circular economy projects, which use field and publicly available data. In this article, we present “BE CIRCLE” as an example for digital services that help to identify new opportunities to cut GHG emissions by closing resource loops. During the development of BE CIRCLE, three case studies with two industrial parks and one port were conducted. The outcomes and learnings are described. In addition, recommendations for data management will be proposed.