Universities rely heavily on co-operation between staff to function effectively. They are complex, interdependent and highly relational organisations which often appear to run on goodwill. Organisational structures, systems and processes play an important role in the delivery of professional support services, but working relationships between university staff members are equally vital. Interpersonal relationships between colleagues at all levels -- academic and professional services alike -- can significantly enhance or constrain the quality of professional support provided on campus. By exploring how relationship dynamics can affect service quality in higher education settings, this article identifies the interpersonal and organisational factors which influence how professional services staff interact with the colleagues they support. This paper shares the results of recent research which evidences the benefits of high-quality relationships and the costs of poor quality ones, helping professional services staff and university managers to better appreciate the experiences and perceptions of internal customers.