This paper examines the multifaceted challenges impeding tax harmonization within the East African Community (EAC) and assesses
the implications for regional integration. Anchored in the EAC Treaty’s mandates to eliminate tax distortions and rationalize
investment incentives, the study investigates the persistent legal, political, and structural barriers that have stalled progress. Key
legal challenges include divergent legal systems (common law, civil law, and hybrid frameworks) across Partner States, discrepancies
in double taxation agreements, and fragmented dispute-resolution mechanisms (e.g., tax tribunals vs. commercial courts). Politically,
rhetorical commitments to integration clash with nationalist protectionism, as states resist ceding tax sovereignty due to fears of
revenue loss and competitive disadvantage. Empirical analysis highlights critical gaps in harmonizing excise duties, where disparate
rates and bases fuel cross-border smuggling and market distortions, and VAT regimes, where coordination remains superficial. The
stalled ratification of the 2010 EAC Double Taxation Agreement—12 years post-signature—exemplifies procedural inertia. Drawing
on comparative insights from the EU and ECOWAS, the paper proposes pathways forward, including phased de jure harmonization
via regional legislation, de facto alignment through judicial precedent, and targeted tax coordination where full harmonization
proves unfeasible. The findings underscore that without resolving these foundational issues, the EAC’s vision of a seamless economic
bloc risks remaining aspirational.