Like concepts of beauty, the presence or absence of economic substance in the tax context often is in the eye of the beholder. More importantly, economic substance means different things to tax authorities in different jurisdictions and the approaches in taxpayer obligations varies widely. This article looks at the concept of economic substance in three separate localities. Stanley C. Ruchelman and Wooyoung Lee look at the U.S., addressing case law establishing the requirement and the 2010 codification of the concept into the tax code. Werner Heyvaert, a partner in the Brussels Office of AKD Benelux Lawyers, and Vicky Sheik Mohammad, an associate in the Brussels Office of AKD Benelux Lawyers, look at the Danish Cases that establish an abuse of rights view for aggressive tax planning – the taxpayer abused rights granted to it by E.U. law – and the Unshell Directive designed to remove certain tax benefits from shell companies. David Payne, Global Head of Governance for Bolder Group, looks at the self-certification rules that have been adopted in the B.V.I., Cayman, and Nevis.