Multiple actors involved in the provision of e‐participation initiatives add to the complexity of organizational design and blur accountability and ownership relations. This study addresses the following research questions: How are different organizations and their units involved in the supply of e‐participation initiatives? How does the multiplicity of actors affect cross‐boundary collaboration, ownership, and accountability relations in the implementation of e‐participation initiatives? The empirical analysis is based on comparative case studies on e‐participation platforms in seven European countries. The case studies indicate that cross‐organizational issues—ownership and accountability, in particular—have often been insufficiently addressed during the development of e‐participation initiatives. Ambiguous ownership and diffused accountability are particularly challenging in the cases of multilevel governance and in “bottom‐up” e‐participation initiatives. The “distance” between the unit responsible for the administration of an e‐participation initiative and the decision‐makers appears to be a critical factor for the functioning of the platforms.