The “S” mark for Tourism Sustainability is a badge created by ICTE to help and guarantee the implementation of the Sustainable Development Goals of the UN 2030 Agenda in tourist establishments, services and destinations. The mark is awarded when the tourist organisation complies with at least one of the following two standards: the Technical Specification for Compliance with the Sustainable Development Goals (SDG) in tourism organisations or the UNE-ISO Standard 21401:2019: Sustainability management system for accommodation establishments. This certification is a guarantee of a sustainable organisation, i.e. organisation that creates economic, environmental and social value in its surroundings in the short and long term, thus contributing to the well-being and progress of present and future generations.