This study delves into the paradoxical nature of corporate sustainability communication. Based on a multiple case study of nine large European firms, we uncover a general paradox of communicating that explains how organizations must both widen the gap between present actions and future aspirations to inspire change and narrow this gap to maintain legitimacy. Moreover, we introduce a typology of five firm responses to this paradox: silent laggard, afraid controversial, separator, integrator, and reframer. Our typology shows how firm responses to the paradox are determined by contextual factors like ownership structure, corporate culture, regulation, and stakeholder pressure. These findings contribute to research on sustainability and paradox in three main ways. First, by introducing the paradox of communicating we provide a novel perspective on temporality that integrates the interdependencies of future and past. Second, we advance paradox theory by proposing a framework that reflects and explains the role of context in navigating paradoxes. Finally, we provide a typology of firm responses to the paradox of communicating arising from conflicting sustainability demands. Thereby, our work also offers important insights for managerial practice of advancing corporate sustainability.