The law applicable to dealings with intangible things is one of the more problematic topics in the English conflict of laws.1 Judicial authority is sparse and ambiguous,2 and writers on the subject have engaged in what Dr Morris described as “an acute conflict of opinion”.3 For voluntary assignments of debts and other claims,4 the difficulties have for many years been alleviated, first, by the United Kingdom’s participation in the Rome Convention on the law applicable to contractual obligations5 and, subsequently, by its decision to opt-in to the EU (Rome I) Regulation on the same subject.6 Those instruments contain, in the Rome Convention, Art.12 and the Rome I Regulation, Art.14, detailed rules to determine the law applicable to issues arising from such voluntary assignments. Notwithstanding the UK’s exit from the European Union, those rules will continue to apply during and after the end of any implementation period.7

It is now clear from the decision of the European Court of Justice (ECJ) in BGL BNP Paribas v Team Bank AG,8 Rome I regime does not afford complete relief from the common law in this area. More specifically, the ECJ held that the Rome I Regulation does not designate, directly or by analogy, the law applicable to the third-party effects of the assignment of a claim in the event of multiple assignments of the claim by the same creditor to successive assignees. That conclusion, although at odds with the treatment in leading English commentaries,9 is wholly unsurprising10 in light of the textual and other considerations to which the ECJ referred.11 It nonetheless leaves English law in an unhappily uncertain state.