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.