This Article undertakes a comparative study of corporate veil piercing doctrines under U.S. corporation and English company law. The Article highlights some fundamental differences between the doctrines in terms of jurisprudential approaches, treatment of specific case types, and other related issues. The Article demonstrates that despite these substantial differences, many English corporate veil cases in fact share a similar analytical approach to the instrumentality doctrine under U.S. law. Therefore, it is possible to construct an English instrumentality doctrine that will bring structure and clarity to the English corporate veil doctrine. The Article concludes with a revival of the much-maligned single economic unit theory, first propounded by Lord Denning. This reformulated theory will provide a more systematic approach to veil piercing cases involving corporate groups.