Digital innovation hubs (DIHs) are a strategic means to drive Euro-pean Small and Medium Enterprises (SMEs) digital transition. The European Commission has envisioned four main functions characterizing DIHs' service portfolios (“Test before invest”; “Support to find investments”; “Innovation eco-system andnetworking”; and “Skills and training”). However, DIHs target dif-ferent functions, e.g. focusing on helping launch novel digital technologies to market, or directing investment opportunities. DIHs are also at different maturity levels, interact with different actors and exist in regions with different conditions for innovation. There might not be an equal need for all four functions, and they might not be equally well served. This studyaims to explore and derive impli-cations for the deployment of the four main functions by DIHs. It builds on the activities ofDIHs involvedin the DIH initiative throughseveral innovation ac-tions, including FED4SAE and HUBCAP.