New ESPP member, LEX4BIO is a Horizon 2020 R&D project, started 1st June 2019. The main goal of the project is to provide a knowledge-based on bio-based fertilisers, in order to secure safe and efficient use of nutrient rich-side streams in European agriculture, reducing the dependency on imported phosphorus fertilisers and energy intensive nitrogen fertilisers. The objectives are to optimise the usage of bio-based fertilisers from side-streams, ensure their safety, build evidence-based trust in their usage and develop legislative framework. LEX4BIO will collect and process regional nutrient stock, flow, surplus and deficiency data, and review and assess the required technological solutions. Furthermore, socioeconomic benefits and limitations to bio-based fertiliser use will be analysed. A deliverable of LEX4BIO will be a toolkit to optimise the use of bio-based fertilisers and to assess their environmental impact in terms of non-renewable energy use, greenhouse gas emissions and other LCA impact categories, In order to facilitate the connection between bio-based fertiliser production technologies and regional requirements.