In the literature, organizational sustainability identity tends to be treated as something that is ‘engineered’ within business organizations through control, reporting, target setting, strategic communication, and other instruments. Through a case study of a company mainly active within the recycling industry, an alternative understanding is given. A distinct organizational sustainability identity is, rather, a social construct based on perceptions of the core operations as “sustainable in themselves” and collaborative work with customers that is perceived as entailing sustainable solutions. Understood in this way, organizational sustainability identity has relatively little to do with formal controls such as codes, policies, reports used by management to position the company as sustainable. Rather, for organizational members, the process of constructing oneself as sustainable builds on convictions about the core operations and the possession of specific capabilities manifested in customer relations. The article adds to current literature through its constructivistic approach and through identifying underlying beliefs that condition the process of forming an organizational sustainability identity.