The Limitation Act 1980 contains a variety of arbitrary limitation periods which apply to particular claims. Unlike the laches defence, these limitation periods are strictly applied without the court having any discretion to determine whether the conduct of the parties is such that the periods should or should not be enforced. Where claimants can sue under a number of different claims, such as unjust enrichment and equitable wrongdoing, the fact that one action is time barred does not prevent them from relying on the other one.2 The question of the appropriate limitation period for restitutionary claims needs to be examined in respect of each type of claim.
(A) REVERSAL OF THE DEFENDANT’S UNJUST ENRICHMENT
(i) The Usual Limitation Period
No specific provision is made in the Limitation Act 1980 for restitutionary claims which are founded on the reversal of the defendant’s unjust enrichment. Consequently, it might be argued that no limitation period should be applicable to such claims. But, as a matter of policy, the claim should fail when sufficient time has lapsed to remove the injustice of the defendant retaining the benefit which was received from the claimant. Therefore, some limitation period is necessary, bearing in mind that the equitable doctrine of laches is generally inapplicable to such claims since it only applies where the claimant seeks equitable relief. A limitation period must be identified therefore by analogy with one of the categories of claim for which the Limitation Act does make specific provision.
By section 5 of the Limitation Act 1980 actions which are founded on contract are barred after six years. The predecessor of this provision was interpreted by the Court of Appeal in Re Diplock as covering actions for money had and received, although ‘the words used cannot be regarded as felicitous’. This conclusion was affirmed by Hobhouse J in Westdeutsche Landesbank Girozentrale v Islington LBC7 on the ground that such actions should be treated as akin to ones relating to contract and so a limitation period of six years is applicable. This is artificial and harks back to the implied contract theory, but, since no specific provision is made for this type of restitutionary claim under the Limitation Act, it is the best solution available. It is certainly better than concluding that such restitutionary actions are subject to no limitation period at all. It is also consistent with the Limitation Act 1623, section 3 of which provided a limitation period of six years for all assumpsit claims and this provision continued to apply until 1939.
Specific provision is made in the Limitation Act 1980 for the recovery of money by virtue of any statute, where the limitation period is six years as well.8 Consequently, restitutionary claims for money under the Law Reform (Frustrated Contracts) Act 1943 are subject to a limitation period of six years. Consistency demands that a similar limitation period should apply to all claims founded on the reversal of unjust enrichment, regardless of the ground of restitution on which the claimant relies.