<p>The luxury fashion industry is currently receiving significant attention with regard to its sustainability practices, especially after COVID-19, as customer demand for sustainable initiatives has increased significantly. Many luxury brands engage in Corporate Social Responsibility (CSR) activities to promote sustainability. However, there is no information available in the literature on the specific sustainable actions they communicate to consumers. This research aims to fill this gap by identifying the sustainable actions communicated by luxury brands, and examining how these actions affect customers' self-congruence, brand attitudes, and trust, as well as their willingness to pay more for sustainable luxury. Based on a content analysis of luxury brands’ websites, the relevant sustainable actions were identified and classified as environmental or social-related actions. Then, through survey data from 460 luxury consumers, the proposed conceptual model was tested. The study identifies two main types of sustainable actions in luxury fashion: environmental and social. These actions have distinct impacts on self-congruity and willingness to pay more for sustainable luxury. Social-related sustainable actions align better with luxury consumer identity, while environmental ones are negatively viewed when consumers seek acceptance for their sustainable purchases. Willingness to pay higher prices for sustainable luxury products is primarily driven by brand trust. The study provides practical guidance to luxury managers on how they can successfully incorporate sustainability in their practices.</p>