There is currently little research into social welfare interventions where children's agency has been in focus and, in particular, a lack of research on children's experiences and perceptions of interprofessional collaboration. Findings from studies that have looked at children's perceptions of opportunities to influence the support they receive have tended to show how they lack power and influence. Drawing on Kuczynski, Harach, and Bernardini's (1999) three principles for investigating and understanding children's agency, the purpose of this study is, in a Swedish context, to explore children's perceptions of their agentic capacity to influence who works with them when many different professionals are involved in providing support. Semi-structured interviews were carried out with 28 children in receipt of support in the form of either home-based interventions, foster or institutional care. The results revealed that, for the older children, perceptions of the exercise of agency involved both the exclusion of certain professionals from the collaborating group as well as the identification of those perceived as being able to help. Additionally, the children's agency could be seen to be implicated in their perceptions of actively making decisions to acquiesce in collaborative solutions. For the younger children, agency was revealed in the way that they interpreted the situations involving collaborating professionals, recognising that it is primarily parents who decide about contact with different 'helpers'. The study provides important insights from the child's perspective into the ways in which, through their agency, children are active in defining and re-defining their own 'organisational chart' of collaboration. Limitations are discussed and proposals for future research are made.