Purpose: The internal customer concept is used with different definitions and purposes in research and in practice – an ambiguity with implications for both scholars and practitioners. The purpose of this study is, therefore, to explore the representation of the internal customer concept in quality management literature and reflect on how the user may affect collaboration in health-care processes, in particular between a service function and health-care staff.

Design/methodology/approach: A review of the internal customer concept in the literature, followed by a conceptual discussion based on previous studies and theories of organizational discourse.

Findings: Three predominant types of relationships related to the internal customer concept were found. The study shows that the ambiguity in the use of the concept may have consequences for the interpretation and application of research results. Potential undesirable consequences with regard to collaboration in processes are discussed.

Originality/value: This study contributes to a new understanding of the internal customer concept in research and practice. As collaboration within and between organizations is increasingly required in many parts of health care, careful considerations become necessary regarding concepts used for relationships to avoid sub-optimization and “us-versus-them” thinking and to strengthen trust-based relationships.