["JCMS: Journal of Common Market Studies, EarlyView. ", "\nAbstract\nThe European Commission builds relationships with civil society organisations (CSOs) through policy‐relevant meetings and funding. Through these relationships, the Commission seeks to obtain expertise, efficient input and legitimacy for its policy initiatives. Despite this, these relationships have become more contested in recent political debates. Studies on funding and access have shown that funding sources – especially public – entail benefits but also dependencies for CSOs and affect access to political institutions. This study analyses how public, private and membership funding sources affect access to the European Commission, thus going beyond the focus on public funding alone. It develops resource exchange theory further through a framework which structurally connects different funding sources with expertise, efficiency and legitimacy. A sample of CSOs from the Transparency register is analysed through regressions. The findings show that CSOs funded by private bodies are more likely to obtain Commission access despite negative associations with legitimacy. The study incentivises consideration of the role of private body funding in EU policy."]