In spite of policy impetus, research shows that teachers struggle to address the increasing diversity in classrooms, among others, due to the lack of competences to deal with it. The acquisition of Intercultural Competence (IC), which could be defined as "the ability to mobilise and deploy relevant attitudes, skills, knowledge and values in order to interact effectively and appropriately in different intercultural situations", is a crucial need for teachers to deal with diversity and to be successful in their teaching. In this context, in 2019 the JRC launched the INNO4DIV project with the aim to support polices in the field of IC of teachers, through the analysis of literature and innovative good practices which have successfully addressed the existing barriers for teacher´s IC development. The conceptual framework presented in this report aims at providing, for the purpose of the research project, a model of reference for the development of IC in teacher's education in Europe. It offers an overview of international frameworks elaborated during the last decade in order to provide teachers with competences for addressing cultural diversity in the classroom, including the UNESCO Intercultural Competence, OECD Global Competence and Council of Europe (CoE) Competence for Democratic Culture frameworks, analysed within the perspective of the EU 2018 European Council Recommendation on Key Competences for Lifelong learning. The first part concludes by posing the CoE Reference Framework on Competences for Democratic Culture as the most suitable framework model for the research purpose, for its comprehensiveness and policy endorsement at EU level. The report also elaborates on the additional requirements for developing IC among teachers, such as institutional support, pedagogical approaches, assessment methods and tools, as well as personal and professional transformation.