Legal Case Summary
Carlill v Carbolic Smoke Ball Co [1893] 1 QB 256
Emphasised the significance of offer and acceptance in contract law; distinguishes between offers and invitations to treat.
Facts
The defendant, the Carbolic Smoke Ball Company, placed an advertisement in a newspaper for their products, stating that any person who purchased and used their product but still contracted influenza despite properly following the instructions would be entitled to a £100 reward. The advert further stated that the company had demonstrated its sincerity by placing £1000 in a bank account to act as the reward. The claimant, Mrs Carlill, thus purchased some smoke balls and, despite proper use, contracted influenza and attempted to claim the £100 reward from the defendants. The defendants contended that they could not be bound by the advert as it was an invitation to treat rather than an offer on the grounds that the advert was: mere ‘puff’ and lacking true intent; that an offer could not be made ‘to the world’; the claimant had not technically provided acceptance; the wording of the advert was insufficiently precise; and, that there was no consideration, as necessary for the creation of a binding contract in law.
Issue
Whether the advert in question constituted an offer or an invitation to treat.
Held
The Court of Appeal found for the claimant, determining that the advert amounted to the offer for a unilateral contract by the defendants. In completing the conditions stipulated by the advert, Mrs Carlill provided acceptance. The Court further found that: the advert’s own claim to sincerity negated the company’s assertion of lacking intent; an offer could indeed be made to the world; wording need only be reasonably clear to imply terms rather than entirely clear; and consideration was identifiable in the use of the balls.
Updated 13 March 2026
This case summary remains legally accurate. Carlill v Carbolic Smoke Ball Co [1893] 1 QB 256 continues to be good law and is a foundational authority in English contract law on offer and acceptance, unilateral contracts, and the distinction between offers and invitations to treat. The principles described in this article — including that an offer can be made to the world at large, that performance of conditions constitutes acceptance of a unilateral offer, and that consideration can be found in the act of using the product — remain firmly established and have been consistently applied and affirmed in subsequent case law. No statutory changes have displaced these principles. The article is suitable for students as a reliable summary of this case.
