Shared clothes represent one example of the sharing economy whereby users provide a variety of clothes to people at fees representing mutual value through online platforms. Sharing creates a more circular economy and represents one form of sustainable consumption. Many studies have proposed environmental concern as a key influencer of customer intention and behaviour, yet other motivations may be driving sustainable consumption behaviours such as sharing clothes. This study aims to expand our understanding of shared clothes in line with attitude–intention–behaviour theory. The aim is to examine the moderating role of environmental concern in the relationship between perceived economic, functional (app quality/platform) benefit, reputation and trust of the app/platform on (a) intention to use online clothes-sharing platforms and (b) spending behaviour of current users of the same sharing platform. A total of 250 and 232 usable questionnaires were gathered from potential and current users of shared clothing. Results reveal that environmental concerns are higher for current users when compared with potential users of the sharing platform. Results of this study identify that personal considerations such as economic benefit outweigh environmental considerations for shared clothes consumers. Practical implications, limitations, and future directions are highlighted.