This report greatly benefited from views, insights, and suggestions of the experts and officials of the Southeast Asian tax authorities at the Webinar on Comprehensive Assessment of Tax Capacity in Southeast Asia on 27 November 2020. The authors thank the Domestic Resource Mobilization Trust Fund for funding support.

Ramesh Subramaniam, Director General of the Southeast Asia Department; Bruno Carrasco, Director General and concurrently Chief Compliance Officer of the Sustainable Development and Climate Change Department; John Versantvoort, Head of the Office of Anti-Corruption and Integrity; and Jose Antonio R. Tan, Director of Public Management, Financial Sector, and Trade Division of the Southeast Asia Department, provided guidance and suggestions in preparation of this report. The authors would like to acknowledge coordination support by Daisuke Miura and Go Nagata, and the excellent research assistance by Gilliane A. De Gorostiza and administrative support by Jennalyn Delos Santos and Rodel S. Bautista.