Inequality by Design argues that, traditionally, EU taxation has treated taxpayers as mere economic agents that handle situations according to principles of formal equality. Cristina Trenta disrupts this rigid neutrality rooted in the economic past by exploring how EU tax law perpetrates social inequality and ignores the distinct, real-world struggles of vulnerable groups. Engaging with the two main models of equality as a central analytical lens, Trenta builds a case for substantive equality over the formal framework and aligns these suggestions with the goals of the UN's Agenda 2030 and the European Charter of Fundamental Rights. Tracing the evolution of EU tax jurisprudence from the perspective of human dignity and worth, chapters prioritize fair outcomes over economic neutrality as a step towards a more equal European society. The book outlines concrete policy recommendations for establishing clear legal definitions for vulnerable groups, implementing gender-responsive budgeting, and ensuring fair representation in Europe's fiscal future. This enlightening book is a valuable resource for students and scholars of development studies, European law, tax law and fiscal policy. Its insights into Agenda 2030 and EU tax law are also beneficial for practitioners and researchers in public finance, tax law and fiscal policy and the sustainable development goals.