Trade liberalisation and the growth of informality have undermined important sources of revenue for many developing countries. Zimbabwe, like a number of other developing countries, has implemented informal sector presumptive taxes in recent years as a way of overcoming this shortfall. This study uses public finance theory to evaluate the equity of presumptive taxes on unregistered small ... [Show full abstract] businesses vis-à-vis formal sector income taxes. In this framework, a good tax is one that treats people with similar incomes in the same way (horizontal equity) and those with different incomes differently (vertical equity). Given the paucity of good quality data required for a comprehensive analysis of equity, this evaluation of presumptive taxes was primarily based on qualitative interviews with 47 informal entrepreneurs and 16 key informants from various government departments. In addition to highlighting the importance for social justice of collecting revenues in a manner that is fair both vis-à-vis the formal sector and within the informal sector itself, a substantial contribution of this study is testing a new qualitative approach to evaluate equity in presumptive taxation, that can be applied in other developing countries with insufficient quantitative data.