Legal Case Summary
Gunthing v Lynn (1831) 2 B7 Ad 232
Contract law – Sale of goods
Facts
The buyer of a horse, who was the plaintiff in this case, promised the seller that they would pay £5 more for the horse, or buy another horse from the seller if the horse was lucky. The horse was not in the condition that the plaintiff believed and a dispute arose between the parties as to whether the seller was owed the conditional payment mentioned by the buyer.
Issue
The court had a number of issues to decide. The most prominent issue was whether the offer from the buyer, to pay more for the horse if it was lucky, could be considered to be a valid offer for the purposes of the sale. This would give an indication as to whether the seller could rely on the payment that had been mentioned. Specifically, the court was required to understand whether the terms ‘lucky’ and ‘buy another horse’ could be defined and considered legally binding on the parties.
Decision/Outcome
The court held that the condition to pay £5 extra for the horse if it was lucky, was deemed to be too vague to create a binding contract between the parties. The words contained in an agreement must be clear so that the parties can be sure of the terms upon they are contracting. As a result of this, the only part of the transaction that was sufficient for the court was the purchase of the horse for the price of £63 and that was the vast majority of the legal agreement between the parties.
Updated 19 March 2026
This article accurately summarises the historical contract law case of Gunthing v Lynn (1831) 2 B & Ad 232, which remains a recognised early authority on the requirement of certainty of terms in contract formation. The principle that contractual terms must be sufficiently certain to be enforceable continues to form part of English contract law and has been developed and confirmed in numerous later cases, including Scammell v Ouston [1941] AC 251 and Baird Textile Holdings Ltd v Marks & Spencer plc [2001] EWCA Civ 274. There have been no statutory or case law developments that undermine the core point illustrated by this case. Readers should note that this is a nineteenth-century case of largely illustrative value and that modern courts apply the certainty principle with greater sophistication, sometimes implying terms or reading agreements purposively to avoid striking them down for uncertainty where possible.
