Unjust Enrichment Claims: A Comparative Overview

This article examines a variety of legal systems with a view to assessing the role currently played within each of them by the principle of unjust enrichment. By focusing on the characteristic features of unjust enrichment claims it seeks to demonstrate that, although there are significant differences between the ways in which different countries handle such claims, there is also much that those systems have in common. While under the common law the principle of unjust enrichment has endured a long struggle for recognition, in civil law systems it has been acknowledged for centuries. This may be because in civil law countries the principle has been expected to play only a residual, and therefore non-threatening, role in the law of obligations while in common law countries it has been called upon, if at all, to serve as the basis for the whole of the law of restitution. We should not assume, however, that all common law systems share one set of characteristics while all civil law systems share another. In some respects there is more in common between systems drawn from each category than there is between systems drawn from the same category. Mixed legal systems, as one might expect, tend to display characteristics drawn from both.