Clauses requiring a party to use best endeavours, reasonable endeavours, all reasonable endeavours and variations on the same theme, are commonplace in negotiated commercial contracts. There is a substantial body of case law dealing with the interpretation of these clauses. An obligation to use best endeavours is more onerous than reasonable endeavours, with all reasonable endeavours falling somewhere in between. However, there remains uncertainty as to the effort required by each type of clause in any particular case. That uncertainty is, at least in part, an inevitable consequence of the approach of the English courts to contractual interpretation.
This article first appeared in the June 2017 issue of PLC Magazine.