Expectations are high for 5G, as it promises many benefits and new business opportunities for all stakeholders engaged in the creation and use of future networks and services. The 5G PPP continues to invest considerable resources into researching and developing the technological side of 5G systems. A relatively recent development is the additional challenge to EU research projects to validate claims about business opportunities through business validation analysis. The challenges for business validation involve using an appropriate analytic approach, as well as the identification of the critical ingredients used for the analysis. Business validation must encompass value propositions for vertical industries, the identification of stakeholders, the emergent roles in the value system, as well as the identification and visualisation of the complex ecosystems that are expected to emerge. In the late fall of 2019, the Working Group “Visions and Societal Challenges” of 5G Infrastructure Association (5G IA) took the initiative to establish the “Business Validation, Models, and Ecosystems” Sub-Group (BVME-SG). On the 25th February 2020 BVME-SG was formally constituted and started a series of meetings to refine the scope and processes of the group. This positioning paper has been collaboratively developed by BVME-SG participants to summarise the findings of those initial meetings. It formally establishes the scope of the group, and key working processes. We draw on some example projects in the 5G PPP portfolio of projects; however, the BVME-SG welcomes new participants from any of the 5G-PPP projects to share knowledge on their project approaches, the challenges, insights and findings so a view on the diversity of approaches can be formed. Future work of the BVME-WG will systematically capture and characterize the methods used for business related considerations of the 5G PPP projects and eventually also capture market estimates, business models and business cases.