Sustainability and digitization are among the major megatrends of our time and – thought together – can create ecological, social and economic benefits for companies. Digitization is crucial for the competitiveness of companies and economies, but it must be consistently aligned with sustainability criteria in order to adequately address ecological guard rails and social consequences. This so-called twin transition was defined by the EU Commission in its Green Deal with sustainable digitization for all sectors, and the German government also set the two major transformation topics of sustainability and digitization as priorities for its Digital Summit 20202. Where do SMEs locate themselves, where are the opportunities and challenges? SMEs see these potentials in principle, but they need an overarching classification as well as a practical reference in order to be able to use sustainable digitization for their own business operations in a target-oriented way: DBU nachhaltig.digital is the place to be.