(A) RESTITUTIONARY CLAIMS FOUNDED ON THE REVERSAL OF UNJUST ENRICHMENT
(i) The Supply of Necessaries
Where the claimant has supplied a minor, who is defined as anybody under the age of 18, with necessary goods or services pursuant to a contract, the claimant is able to recover the reasonable value of these necessaries even though the contract itself is unenforceable. It is clear therefore that the restitutionary claim will succeed and the minor has no defence of incapacity.
(ii) The Supply of Non-Necessary Benefits
Where the claimant has transferred benefits to a minor which cannot be characterized as necessaries the claimant is unable to enforce the contract against the minor. The traditional view is that the claimant will not be able to bring a restitutionary claim against the minor for the value of the benefit transferred because the defendant has a defence of minority. Although this defence has been recognized in a number of cases, careful analysis of them suggests that their conclusions are highly dubious in the light of later developments in the law of restitution.
(1) Decisions Which Recognize a Defence of Minority
The leading case which suggests that the defendant’s minority is a defence to restitutionary claims is Cowern v Nield, where the claimant paid the defendant, who was a minor, a sum of money for goods which the defendant subsequently failed to deliver. The claimant sued to recover the money on the ground of total failure of basis, but the claim failed because the court concluded that it was not possible to imply a contract between the minor and the claimant since this would result in the indirect enforcement of a contract which was void. Similarly, in R Leslie Ltd v Shiell8 the claimant had lent money to the defendant minor, who had made a fraudulent misrepresentation as to his age. The claimant sought to recover this money but was unable to do so, again on the ground that the court would not indirectly enforce a contract which was void by reason of the defendant’s incapacity.9
The problem with the reasoning in these cases is that it is founded on the fact that the court would not imply a contract to make restitution where that contract was void. But the implied contract theory of restitutionary claims was rejected by the House of Lords in United Australia Ltd v Barclays Bank Ltd.10 It is now clear that the obligation to make restitution is imposed as a matter of law  and has nothing to do with the enforcement of any actual or implied contract between the parties. It follows that, if the claimant had been awarded restitutionary relief in these cases where the defendant was a minor, this would not have infringed the particular legal policy which stated that any contract made between the parties was unenforceable.
(2) Should a Defence of Minority Be Recognized?
Although the reasoning in the cases which have recognized a defence of minority can be rejected, it is still necessary to consider whether, as a matter of policy, the defendant’s minority should operate as a defence to a restitutionary claim. Whilst it is true that minors require some protection against the consequences of entering into foolish transactions which they are not able to detect because of their immaturity, the minor should not be over-protected, since this may cause injustice to the party with full capacity. It follows that a restitutionary claim against a minor should only be defeated where there is a danger of the minor being unduly prejudiced by virtue of the obligation to make restitution. Such prejudice will not occur where the minor still has the benefit or its product which the claimant had transferred to him or her, since the minor can justifiably be expected to return that which he or she had no right to retain. Where, however, the minor has dissipated the benefit, he or she could be prejudiced if he or she was required to make restitution to the claimant, since the minor would need to find the value of the benefit from his or her own resources. But in circumstances such as this there is no need for the restitutionary claim to be defeated by a defence of incapacity, because the defence of change of position would presumably be applicable. Perhaps the defence of change of position should be interpreted more flexibly where the defendant is a minor, to give him or her greater protection against restitutionary claims than is available where the defendant is an adult. So where, for example, the minor has received a sum of money from the claimant to purchase necessaries and the minor wastes the money on extravagant parties, this might enable the defendant to rely on the defence of change of position even though the defence would not have been available had the defendant been an adult, because it would not have been equitable to allow the defence to succeed. Consequently, the fact that the defendant was a minor should be taken into account when determining whether the change of position defence should succeed.
There was no obvious policy reason why the restitutionary claim should have failed in both Cowern v Neild and R Leslie Ltd v Shiell, because there was nothing to suggest that the award of a restitutionary remedy would have prejudiced the minor. In Cowern v Nield the minor had received money for goods which he had failed to deliver and, assuming that he had not changed his position, he should have been required to repay this money to the claimant. Equally, in R Leslie Ltd v Shiell if the minor had been obliged to repay the claimant the sum of money he had borrowed at a reasonable rate of interest the claimant could not be considered to have taken advantage of the defendant’s minority in any way.
It follows that there is no role for a defence of minority where the restitutionary claim is founded on the defendant’s unjust enrichment, since the defence of change of position, perhaps interpreted more liberally than normally, would give the defendant adequate protection against the restitutionary claim.
-  4 See the Sale of Goods Act 1979, s 3(2) which applies to the sale and delivery of goods which can be
-  characterized as necessaries.
-  See p 300, above. 5 See p 384, above.
-  7  2 KB 419. See also Bristow v Eastman (1794) 1 Esp 172, 170 ER 317.
-  8  3 KB 607. 9 Ibid, 612 (Lord Sumner).
-   AC 1.
-  See Westdeutsche Landesbank Girozentrale v Islington LBC  AC 669, 688 (Lord Goff).
-  See p 690, above.