As summarised in: Restitution and unjust enrichment—overview, restitution is concerned with reversing one party’s unfair or unjust benefit obtained at the expense of another party.

Practice Note: Restitution for unjust enrichment—elements of the claim sets out the key Requirements when bringing a claim for unjust enrichment. It is not a prerequisite to a claim for unjust enrichment that the defendant must have acted in a wrongful way, but that their Retention of the gain they have obtained at the claimant’s expense is unjust. This may be, eg, where the claimant mistakenly made a payment to the defendant through no wrongful act on the part of the defendant.

Practice Note: Defences to restitutionary claims includes, among available defences, the defence that the defendant has changed their position as a result of the enrichment or that the defendant is a bona fide purchaser for good value, itself having given good consideration for that which it has received, even if this has been at the claimant’s expense.

However, there are other claims for restitution which are predicated on some element of