Interprofessional collaboration and practice (IPCP) is considered the cornerstone for effective service delivery for children with speech language and communication needs (SLCN). Following Stutsky and Spence Laschinger’s framework, we investigated IPCP-related differences between Dutch and Norwegian professionals in a cross-national comparative survey study. The personal relational skills of communication, trust and situational factor support structures were related to interprofessional collaboration in both countries. Trust was a stronger predictor for the Dutch sample than the Norwegian sample. A moderated moderation analysis revealed that the relationship between IPCP and perceived team effectiveness is moderated by trust for the Dutch professionals but not for their Norwegian colleagues. Trust may play a vital role for interprofessional teams in the Dutch context because service delivery is mainly characterised by the pull-out intervention of specialised professionals. In the integrated early intervention context of Norway, emphasis on professional communication skills seems a fruitful strategy to enhance the effectiveness of teams. Early intervention service delivery may be strengthened by structural facilitation and building networks to develop trust across professionals and organisations, which supports the development of professional competence relevant to IPCP in early intervention service delivery.