The speeches in the House of Lords case of United Scientific Holding Ltd v Burnley Borough Council) [1978] AC 904 were strictly obiter on the presumption against time being of the essence in relation to the service of a rent review notice, but the High Court held that they were nevertheless authoritative on that point.

The principle that there is a rebuttable presumption that time is not of the essence, is a general principle that applies to all rent review clauses.