In this paper, we outline the structure and content of a code of ethics for companies engaged in data-based business, i.e. companies whose value propositions strongly depends on using data. The code provides an ethical reference for all people in the organization who are responsible for activities around data. It is primarily targeting private industry, but public organizations and administrations may also use it. A joint industry-academic initiative, involving specialists for ethics as well as for all relevant data-related issues, developed this code.