Within the IS research field, there are many views on how to understand the use of IT systems. Within the community of organisational semiotics, Stamper’s semiotic framework has been used as a tool to understand information systems at different abstraction levels. Another theory related to organisational semiotics, Information Systems Actability Theory (ISAT), argues that social action theories and speech act theory are needed for a thorough understanding of the use of IT systems in organisations. The use of IT systems is considered to be performance of action within a social context. The purpose of this paper is to elaborate on user interfaces of information systems as a means to understand socio-pragmatic and communicative aspects of IS use. The theoretical foundation is based on semiotic and socio-pragmatic theories, and findings from a case study are presented and discussed in order to clarify the argumentation.