‘Social Investment’ continues to attract significant amounts of rhetoric, policy focus, financial support and media coverage. Yet social investment is often understood inconsistently, narrowly and inaccurately. In our work on Accessing Mainstream Finance, we are exploring how banks actually provide significant amounts of finance to social enterprises and charities. But finance doesn’t just come from specialist social investment funds or from banks. Social enterprises and charities can also access finance from a range of places, from friends and family, from emerging web-based platforms and new peer-to-peer models, from ‘the crowd’, from local authorities and elsewhere. We want to shed light on the scale and terms of ‘uncharted’ social investment. This will bring greater clarity to the field, which will, in turn, enable community businesses and social organisations, investors and policymakers to better target their efforts to make finance more accessible and affordable.