Change of Position and Commercial Reliance in English Law

Abstract

The defence of change of position plays a critical role in balancing claimant and defendant interests in unjust enrichment claims. This article examines the treatment of commercial reliance within the English law defence, focusing on cases involving mistaken payments, revenue recovery, and financial intermediaries. It analyses whether English courts have adopted a consistent standard for assessing reliance and detriment, particularly in institutional and corporate contexts. The article argues that judicial reasoning has oscillated between strict and flexible approaches, creating uncertainty for commercial actors. By evaluating recent authority, the article proposes a principled framework for assessing commercial reliance that preserves fairness while promoting predictability. The article concludes by considering the future development of the defence in English law.