Children and other vulnerable parties such as those with a cognitive, social or communication impairment frequently struggle to understand, and be understood in, the criminal justice environment. One way this has been addressed in jurisdictions around Australia and overseas is through the introduction of intermediary (or communication partner) schemes, whereby an independent third party assists vulnerable witnesses, and in some cases, defendants, with their communication needs. The South Australian Government introduced a trained volunteer communication partner scheme for defendants and prosecution witnesses as one element of its Disability Justice Plan in 2016. However, the scheme had relatively limited use and ceased operation on 1 March 2020. This study provides a qualitative analysis of stakeholders’ (N = 23 professionals) perceptions of how the scheme was implemented, the factors that constrained the usefulness of the scheme and how the initiative could be improved. Participants highlighted the need for a future communication partner service to include highly trained and specialized professionals situated within a government agency.