Oral variation - possible even where the contract says not?

In a recent decision, based on principle rather than commerciality, the Court of Appeal has considered the law regarding the effect of clauses prohibiting oral variation of agreements. It has held that, even if a clause says an agreement can only be amended in writing, it can still be amended orally, or by conduct.

This decision means that though such clauses remain useful, they can no longer be relied upon definitively. Though the court’s comments were obiter, they may be decisive in any future case where this is an issue. Commercial parties will therefore need to remain vigilant to ensure that, despite the existence of such clauses, they do not unwittingly vary agreements by what they say and do.