Unjust enrichment - defendant refusing to return cherished number-plate obtained by sellers' mistake - defendant receiving 'readily returnable' benefit

Coys of Kensington Holdings Ltd v McDonald: CA (Lords Justice Thorpe and Mance and Mr Justice Wilson): 5 February 2004

The claimant car auctioneers were instructed by the parents and executors of the late owner of a car with a cherished number-plate to sell the car without the number-plate.

By mistake, the purchaser obtained the number-plate with the car.

He refused to return the plate and had passed it on to his partner.

The executors sued the claimant, which joined the purchaser as a part 20 defendant, but subsequently assigned the cause of action to the claimant.

The judge found that the purchaser had been unjustly enriched by receiving, at the expense of the deceased's estate, a benefit in the form of the plate which he knew, or ought to have known, he was not entitled to have.

The purchaser appealed on the ground, among other things, that he had not, on a true construction, received any 'benefit'.

Joshua Swirsky (instructed by S Newman & Co) for the purchaser; James Purchas (instructed by Wilmot & Co, Cirencester) for the claimant.

Held, dismissing the appeal, that, where unjust enrichment was alleged, one of the questions to be asked was whether the defendant had benefited or been enriched; and that, whatever else might constitute a 'benefit', it was clear that the law must in any event recognise, as a distinct category, enrichment cases where there was a 'readily returnable' benefit, of which the instant case was an example.