The purpose of this study is to examine the relation between online communication in marketing and customers’ purchase pressure. We further examine if the customer’s perception of the brand’s authenticity and genuineness affects the perceived purchase pressure. This will be examined within sustainable brands that have a focus on changing customers’ consumption patterns, with the assumption that they do not wish to create purchase pressure from a sustainability standpoint. By examining what causes purchase pressure we intend to contribute to developing the academic definition of the term. This is done by using an exploratory, inductive research design in which a qualitative research method has been applied. A qualitative content analysis was conducted to give insight in how sustainable brands marketing communicated contributes to the phenomenon of purchase pressure. Purchase pressure in the context of sustainable fashion is inherently negative as it indirectly is connected to overconsumption. Different cues have been revealed in this study to contribute to customers' purchase pressure, as well as that the authenticity and genuineness of a brand plays a role in the perceived pressure.