The UN Sustainable Development Goal (SDG) 4 enjoins countries to ‘promote lifelong learning opportunities for all’ (UN DESA, 2022). It thereby establishes lifelong learning (LLL) as central to a sustainable future. Transforming higher education institutions (HEIs) into lifelong learning institutions is key to realizing this goal. HEIs are in a unique position to promote sustainable societies through their expertise in knowledge production, skills development and academic exchange. By expanding access to new populations of students, HEIs can promote LLL throughout the wider society. This policy brief provides insights on principal areas of action for policymakers and other key stakeholders. It highlights the importance of enabling policy environments at the national and institutional level, looks at institutional structures and mechanisms, and evaluates different ways of widening access and increasing participation to foster the transformation of HEIs into lifelong learning institutions.