may be regarded as unjust are that the benefit has been conferred by mistake or due to a misrepresentation, by compulsion. Moreover, subsequent events may unfold in such a way that a benefit is conferred in circumstances which suggest that to allow it to be retained would create injustice. Mistake

It has been seen already that at common law, the effect of a common mistake is to render a contract void.14 In terms of restitution, this is not the end of the tale, since a consequence of the mistake may have been a payment by the claimant to the defendant. If losses were left to lie where they fall, the consequence would be an unjust enrichment of the defendant. However, an order for return of any moneys paid will serve to reverse the defendant’s enrichment. Thus, if the parties enter into a contract of insurance which fails because at the time of contracting neither party was aware that the subject matter of the contract was non-existent, the insured will be able to recover back any premium he has paid under the mistaken belief that the contract was valid, on the basis that either the consideration has wholly failed15 or that money has been paid and received under a mistake of fact.16 In terms of restitutionary principles, both of these alternative approaches can be justified since an operative mistake renders the contract void in which case a payment by the claimant to the defendant needs to be disgorged and a total failure of consideration means that there is no value given in return for a payment made