This paper investigates the relationship between individuals’ attitudes towards fairness and their views about tax compliance in developing countries. It argues that individuals’ attitudes regarding fairness shape their views about paying taxes and their ethical stances regarding tax evasion. Using survey data for 18 major cities in Latin America, we find that individuals who are highly sensitive to fairness are less likely to consider paying taxes as a civic duty and more likely to justify tax evasion. These attitudes towards tax compliance are not inelastic. We also find evidence that individuals’ beliefs about reciprocity and merit mediate the effect of fairness on personal views about tax compliance. Finally, this paper shows that the heuristics people use to explain their position in the income distribution make them more or less sensitive to inequality, and it affects their tax morale. These findings help us better understand the concept of reciprocity and provide valuable lessons on the urgent task of expanding fiscal capacity to promote economic growth and inequality in developing countries.