Briefly stated, the restitution interest represents the interest a claimant has in the restoration to him of benefits that the defaulting party has acquired at his expense. In general, the gain to a defendant from a breach of contract is irrelevant to the quantification of damages. However, as a result of the decision of the House of Lords in Attorney-General v Blake [2001] 1 AC 268, it is now clear that there are at least certain circumstances in which a claimant can recover the profit which the defendant has made from his breach of contract. Blake, a former member of the intelligence services, undertook not to divulge any official information gained as a result of his employment and broke the undertaking by publishing his memoirs, No Other Choice. The Crown sought to recover the royalties he was to be paid by his publishers. Their Lordships confirmed that, in general, damages were measured by the claimant's loss but held that in an exceptional case the court can require the defendant to account to the claimant for benefits received from a breach of contract. In determining whether to order an account for profits, Lord Nicholls (with whom Lord Goff and Lord Browne-Wilkinson agreed) stated:

An account of profits will be appropriate in exceptional circumstances. Normally the remedies of [compensatory] damages, specific performance and injunction, coupled with the characterisation of some contractual obligations as fiduciary, will provide an adequate response to breach of contract. It will only be in exceptional cases, where those remedies are inadequate, that any question of accounting for profits will arise. No fixed rules can be prescribed. The court will have regard to all the circumstances, including the subject matter of the contract, the purpose of the contractual provision which has been breached, the circumstances in which the breach occurred, the consequences of the breach and circumstances in which relief is being sought. A useful general guide, although not exhaustive, is whether the plaintiff had a legitimate interest in preventing the defendant's profit-making acitivity and, hence, in depriving him of his profit. The inadequacy of other remedies thus appears fundamental to the award of an account of profits. The claimant must also show that he has a 'legitimate interest' in depriving the defendant of his profit.

The Crown was held to have such a 'legitimate interest' in Blake, and no other remedy was adequate on the facts. If restitutionary damages had not been awarded, the Crown would have recovered nothing since they had suffered no loss.