This chapter draws on insights gained from participant observation and elite interviews with activists, policy makers, private sector practitioners and other non-specialist non-governmental organisation professionals to describe the role played by the Tax Justice Network (TJN) in raising the salience of tax issues on the political agenda. In so doing, the chapter specifies the peculiar constellation of actor attributes, organisational forms and organising that can help explain issue adoption, policy influence and accelerated policy innovation in what has until recently been a technical policy domain largely impervious to civil society activism. This aim is advanced by developing frameworks to describe the role of NGO activity in global wealth chains (GWCs) focusing on economic justice issues. We find that, owing to the fast-changing, technically complex and cross-disciplinary nature of the tax policy arena, the effectiveness of larger NGOs may be muted by burdensome bureaucratic procedures. Rather, our analysis of the Tax Justice Network suggests that, in this context, smaller NGOs may pack a bigger punch.