The assertion of contractual rights may be defeated by the illegality defence, not because their creation is offensive to public policy but by reason of an illegality that ‘taints’ these rights. To date, no analytical framework has been developed for understanding how these tainting rules are connected to one another. The Tainting Illegality Framework (TIF) presented in this paper seeks to fill this gap in current legal scholarship by exploring, first, the linkages between the rules by which contract rights are tainted and, secondly, the theoretical underpinnings that explain the existing tensions and that will continue to shape the law in this area. The suggested analytical approach enriches and increases the sophistication of the current approaches by considering how their application is shaped by considerations of proximity and the nature of the contaminating illegality. The framework recognises the value of the existing rules, and seeks to enrich the analytical approach by suggesting how their application can more transparently reflect the policy rationale for applying the illegality defence.