One in seven of the world's population live in informal settlements in urban areas. More than this are probably in poverty. But the scale and depth of poverty is underestimated by most governments and international agencies and this helps underpin ineffective policies. This is made worse by the lack of voice for low-income urban dwellers and their lack of influence within governments and aid agencies. With our partners and informed by the work of federations of slum/shack dwellers, we are transforming the understanding of urban poverty, its causes, and how best to address it, and to change misleading views about urbanisation and rural change.