Parties to commercial contracts often insert a “no oral modification” (or NOM) clause to prevent attempts to undermine written agreements by informal means. Such clauses are intended to prevent contracting parties being bound by subsequent variations unless the specified formalities (for example, it is fairly typical in commercial contracts that a variation must be recorded in writing and signed by the parties) are complied with.
In the recent decision of Rock Advertising Limited v MWB Business Exchange Centres Limited  UKSC 24, the UK Supreme Court unanimously held that an agreed oral amendment to revise the terms of a payment schedule to a lease contract, which contained a NOM clause, was ineffective. The majority of the UK Supreme Court based its reasoning on the broad proposition that the law should give effect to contractual provisions which required specified formalities to be observed to recognise a variation. Lord Sumption (who gave the judgment for the majority) disagreed with the Court of Appeal’s view that recognising the oral variation, despite the NOM, promoted party autonomy. On the contrary, he found that the effect of the Court of Appeal’s ruling was to override the contracting parties’ intentions such that they would be unable validly to bind themselves as to the manner in which future changes in their legal relations were to be achieved, however clearly they originally expressed their intentions in that regard.
While the UK Supreme Court was aware that its decision may cause injustice to a party who had relied on the orally varied contract to its detriment, it pointed out that various doctrines of estoppel would provide a safeguard in appropriate cases.
The Court also commented, by way of obiter dictum, on the rule in Foakes v Beer (which provides that part payment of a debt is not good consideration for the release of the whole) to the effect that to depart from the rule would require a re-examination of the decision in Foakes v Beer and while “it is probably ripe for re-examination“, it should be a matter for an enlarged panel of the Court.
For more details, please see our blog post on the Supreme Court judgment here.