Traditionally, liability for breach of trust where a trustee misapplies the trust assets was dealt with in terms of the trustee’s liability to account; in particular, the beneficiary could falsify the account, with all that entailed regarding the rules of ‘restoration of the trust fund’. However the UK Supreme Court decision in AIB Group (UK) Plc v Mark Redler & Co Solicitors, suggests that henceforth liability is to be assessed on a ‘but for’ consequential loss basis, in view of the fact that the transactions at issue were essentially commercial or contractual in nature. The main claim of this chapter is that, in the same way that a ‘performance interest’, distinct from an interest in compensation for consequential loss, is widely recognised in contract law doctrine, the traditional law on breach of trust can also be illuminated by focussing on the beneficiary’s interest in the trustee’s performance of his trust obligation. Yet AIB may reflect a broader trend in the UK common law in view of the 2016 UK Supreme Court decision in Bunge SA v Nidera BV to give less effect to the performance interest.