A more recent version of these Defences To Unjust Enrichment notes – written by Oxford students – is available here.
The following is a more accessble plain text extract of the PDF sample above, taken from our Aspects Of Obligations Notes. Due to the challenges of extracting text from PDFs, it will have odd formatting:
1 UNJUST ENRICHMENT (III): DEFENCES
Estoppel will arise where D detrimentally changes his position in reliance of a representation made by C that a benefit was validly received. This is a complete bar because its effect is to stop C arguing that the elements of unjust enrichment have been established United Overseas Bank v Jiwani (1976) (HC) - McKenna J - three conditions must be satisfied:  D led to believe that he or she is entitled to a benefit,  D relies on this,
 D's circumstances have changed so that restitution would be inequitable
Justice of the Case United Overseas Bank v Jiwani (1976) (HC) - McKenna J - estoppel will still fail if it is not just to require D to make restitution to C, e.g. if D was under a duty to inform of the mistake
Defendant Led to Believe He Is Entitled to a Benefit
Must have been an unequivocal representation or a duty of accuracy to D which C breached RE Jones v Waring and Gillow (1926) (HL) - Lord Sumner - these are cumulative conditions and both must be satisfied in every case
The better view is that they are alternative: United Overseas Bank v Jiwani (1976) (HL) - McKenna J - assumed that these are alternative conditions
Representation of Fact RE Jones v Waring and Gillow (1926) (HL) - representation must be collateral to the transfer and cannot be implied from the mere fact of voluntary transfer. It must be made by C rather than a third party
Representations of fact may be express or implied
Buy the full version of these notes or essay plans and more in our Aspects Of Obligations Notes.