"Around 23 million adults in Europe left school before completing lower secondary education (Eurydice Report 2015 'Adult Education and Training in Europe'). The Second Chance Schools for adults participating in this project have, for several years, been providing learning opportunities to this target group using Project-Based Learning (PBL) and entrepreneurship education. This combination, also known as Entrepreneurship-Based Learning (EBL), has proven to be very effective with this target group so we wanted to develop a whole curriculum of adult lower secondary education (ISCED 2) based on EBL. To do so the first step was to train our teachers. However, there were no training opportunities for teachers on how to develop and implement a whole curriculum of adult lower secondary education based on EBL.In this context, the objective of the project was to develop the first open and multilingual online course on Entrepreneurship-Based Learning (EBL) for teachers of adult lower secondary education (ISCED 2).The online course is divided in 4 units:Unit 1: introduction to Entrepreneurship-Based Learning (EBL) in adult lower secondary education.Unit 2: methods, tools and supporting materials for EBL in adult lower secondary education.Unit 3: model lesson plans for EBL in adult lower secondary education.Unit 4: assessment and recognition of the learning outcomes from EBL in adult lower secondary education using the EU transparency and recognition tools for skills and qualifications.Once the first development of the online course was completed, it was tested by the three second chance schools for adults: 6 teachers and 47 students in total participated in the testing. Based on the testers’ feedback, the project partners implemented additional improvements before the final publication of the online course in August 2020.The online course is hosted in an e-learning platform, accessible from computers, tablets and smartphones. The platform is available in five EU languages: English, Spanish, French, Hungarian and Romanian at www.enchance.eu.Beyond the partners, the online course has the potential to be exploited by a wide range of organisations and individuals from the fields of education and training across Europe. Thanks to its publication as an Open Educational Resource under the Creative Commons license “Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)"", anyone is allowed to, not only use it for free, but also to modify it and adapt it to other target groups. Therefore, the online course will serve as the impulse for future innovations and developments in the fields of education and training across Europe. As a result, the project steps a stone towards a fully inclusive European society where every person has access to high quality education.This cross-sectoral and cross-border partnership is an initiative of Fundacion Marcelino Champagnat (Spain) in collaboration with Établissement Public Local d'Enseignement et de Formation Professionnelle Agricole de RETHEL (France), Belvárosi Tanoda Alapítványi Gimnázium (Hungary) and Media Partners (Romania). The EnChance project has been co-funded by the Erasmus + Programme of the European Union."