In recent years, there has been a notable shift towards increased citizen participation in society, both globally and within the Netherlands. Concurrently, urban development has undergone a notable shift towards a more private-led orientation over the decades. This shift is evident in the expanding responsibilities of the private sector, particularly project developers, which now extend beyond traditional boundaries. One manifestation of this transformation is the increasing organization of citizen participation by private developers, referred to as private-led participation, highlighted by the new Environmental and Planning Act implemented in January 2024. As responsibilities evolve and the lines between the public and private sectors blur, there is a noticeable convergence of objectives and actions. This growing interdependence in private-led participation processes calls for greater collaboration across organizational boundaries between developers and municipalities. Despite these developments, limited academic research and practical tools address the evolving roles of public and private actors and their collaboration in private-led participation processes. Therefore, this study aims to explore the changing roles of private developers and municipalities in private-led citizen participation processes. Specifically, it seeks to investigate how these stakeholders can collaborate to facilitate private-led citizen participation. The primary method for this study will be qualitative research, involving a comprehensive literature review and multiple case studies within the Municipality of Amsterdam. This approach will include document analysis along with in-depth interviews with developers and municipalities. The study aims to provide practical recommendations for enhancing collaboration between private developers and municipalities in the context of shifting roles, ultimately facilitating private-led participation processes. The research concludes that with developers increasingly taking the lead in managing private-led participation processes, municipalities remain crucial roles in setting the stage, providing guidance, and offering strategic oversight. Collaboration between the two requires separate but also shared responsibilities, clear role definitions, early engagement, transparent communication, clear preconditions and capacity building to ensure private-led citizen participation.