The Constitutionality of Exit Taxes: A Comparative Perspective

The issue of exit taxes has recently become more salient in both the United States (US) and the United Kingdom (UK), albeit for very different reasons. As a Member State of the European Union (EU), the UK was subject to strict constraints under EU law on its ability to enact an exit tax on individuals transferring their residence to other Member States. These constraints have now largely disappeared, with the consequence that renewed attention is being given to the possibility of the UK’s introducing an exit tax along the lines of those already in place in the US, Canada, Australia and elsewhere. At the same time, the US exit tax is coming under pressure and is likely to be challenged as unconstitutional in the wake of the US Supreme Court’s decision in Moore v United States (Moore).1 This article will evaluate whether such a challenge can succeed and compare the tightening of constitutional restrictions in the US with their loosening in the UK.