The reform of bank supervision represents one of the great institutional challenges for the European Union. The recent pattern of cross-border failures in supervision refl ects the extent to which a better functioning system of supervision is critical for the safe operation of the banking system in the EU. Within this framework, the main institutional reforms currently being proposed are likely to fail. It is thus worth considering alternatives. This paper explores the merits of a choice-oriented approach under which individual Member states have the option to delegate prudential supervision of their largest banks to the European Central Bank, while still retaining the right to re-assume such a role at a later date. Responsibilities, commitments and costs would be allocated by means of a binding agreement with the ECB that can be tailored to Member states’ specifi c circumstances, to the extent permitted by supervisory coherence and equal treatment. The proposal offered here is superior to existing supervisory arrangements, and is likely to produce a more socially desirable outcome than the proposed alternatives.