Smaller, more targeted, and more flexible than traditional education and training programmes, micro-credentials have become a prominent feature of education, training and labour market policy discussions in recent years. Several OECD countries have already started the development of national micro-credential ecosystems, and many others are looking to follow suit. This OECD Education Policy Perspective serves as Part B in a two-part series of summary papers. The first publication, Paper A, examined the evolving landscape of micro-credentials, with a particular focus on the development of public policies that can foster effective utilisation of micro-credentials for lifelong learning, upskilling and reskilling. This publication, Paper B, presents case studies from four European Union Member States – Finland, the Slovak Republic, Slovenia and Spain. The document was authored by Roza Gyorfi and Shizuka Kato from the OECD Higher Education Policy Team and Thomas Weko from George Washington University.