This chapter sets out a theory of social assistance (including social cash transfers), which covers both the global North and South, and discusses the future of income security in the South beyond social cash transfers. It is argued that social assistance constitutes a small but vital component of social security and social citizenship—‘residual but fundamental’. It is further argued that social assistance is ‘fundamental but not comprehensive’, i.e. the challenge of universalizing social citizenship extends beyond relieving poverty. To confront the problem of inequality and get the middle classes on board, cash transfers need to be embedded in a broader, multi-tiered architecture of social security, which increases political support also for cash transfers. Still, despite the fundamental contributions of social assistance and the positive effects of cash transfers in many countries of the South, these programmes remain Janus-faced, entailing inclusions and exclusions, recognition and stigma, autonomy and social control.