This paper compares and analyses the approaches to unitary taxation in federal and regional integrated markets. It also explores the potential application of unitary taxation in the context of regional economic communities within Africa, East Asia, and Latin America. The federal models to be examined are the systems of unitary taxation in practice in the United States(US), Argentina, Canada and Switzerland. The primary regional model to be examined is the Common Consolidated Corporate Tax Base (CCCTB), now proposed in the European Union (EU). Finally, this paper extrapolates lessons learned and explores the potential application of unitary taxation in the Association of Southeast Asian Nations (ASEAN), the East African Community (EAC), and Mercosur and the Andean Community (CAN) in the Latin American region.