Carlill v Carbolic Smoke Ball Company 1 QB 256 is an English contract law decision by the Court of Appeal, which held an advertisement containing certain terms to get a reward constituted a binding unilateral offer that could be accepted by anyone who performed its terms. It is notable for its treatment of contract and of puffery in advertising, for its curious subject matter associated with medical quackery, and how the influential judges (particularly Lindley and Bowen) developed the law in inventive ways. Carlill is frequently discussed as an introductory contract case, often one of the first cases a law student studies in the law of contract.
The case concerned a purported flu remedy called the "carbolic smoke ball". The manufacturer advertised that buyers who found it did not work would be awarded £100, a considerable amount of money at the time (equivalent to over £11,000 in 2026). The company was found to have been bound by its advertisement, which was construed as an offer which the buyer, by using the smoke ball, accepted, creating a contract. The Court of Appeal held the essential elements of a contract were all present, including offer and acceptance, consideration and an intention to create legal relations.
Facts The Carbolic Smoke Ball Co. made a product called the "smoke ball" and claimed it to be a cure for influenza and a number of other diseases. (The 1889–1890 pandemic ongoing at the time was estimated to have killed 1 million people, but may have been caused either by influenza or a coronavirus.) The smoke ball was a rubber ball with a tube attached. It was filled with carbolic acid (now known as phenol). The tube would be inserted into a user's nose and the ball would be squeezed at the bottom to release the vapours.
The Company published advertisements in the Pall Mall Gazette and other newspapers on November 13, 1891, stating that it would pay £100 () to anyone who got sick with influenza after using its product according to the instructions provided with it:
Louisa Elizabeth Carlill saw the advertisement, bought one of the balls and used it three times daily for nearly two months until she contracted the flu on 17 January 1892. She claimed £100 from the Carbolic Smoke Ball Company. They ignored two letters from her husband, a solicitor. On a third request for her reward, they replied with an anonymous letter that if it is used properly the company had complete confidence in the smoke ball's efficacy, but "to protect themselves against all fraudulent claims", they would need her to come to their office to use the ball each day and be checked by the secretary. Carlill sued for breach of contract, her counsel arguing that the advertisement and her reliance on it amounted to a binding contract between her and the company, and that the company should therefore pay the promised £100. The company argued that they had made no legally binding offer which was capable of acceptance, and thus there could be no contract.
Judgment
The Carbolic Smoke Ball Company, represented by H. H. Asquith, lost its argument at the Queen's Bench, which decision was then appealed. The Court of Appeal unanimously rejected the company's arguments and held that they had made a binding contract with Carlill. Among the reasons given by the three judges were: (1) that the advertisement was not a unilateral invitation to treat to all the world, but rather an offer restricted to those who acted upon the terms set out in the advertisement; (2) that satisfying the stated conditions for using the smoke ball constituted acceptance of the offer; (3) that purchasing or merely using the smoke ball constituted good consideration, because it was a distinct detriment incurred at the behest of the company and, furthermore, more people buying smoke balls by relying on the advertisement was a clear benefit to Carbolic; and (4) that the company's claim that £1000 was deposited at the Alliance Bank showed the serious intention to be legally bound. 1 Q.B. 256, 262-275
Lord Justice Lindley Lindley gave the first judgment. He made short shrift of the insurance and wagering contract arguments that were dealt with in the Queen's Bench.
He follows on with essentially five points. First, the advertisement was not "mere puff" as had been alleged by the company, because the deposit of £1000 in the bank evidenced seriousness.The leading case of the time, which said that mere advertising "puff" did not create actionable warranties is Dimmoch v Hallett (1866) 2 Ch. App. 21. It follows the Latin maxim simplex commendatio non obligat, that "simple commendations do not create obligations." Second, the advertisement was an offer made specifically to anyone who performed the conditions in the advertisement rather than a statement "not made with anybody in particular." Third, communication of acceptance is not necessary for a contract when people's conduct manifests an intention to contract. Fourth, that the vagueness of the advertisement's terms was no insurmountable obstacle. And fifth, the nature of Carlill's consideration (what she gave in return for the offer) was good, because there is both an advantage in additional sales in reaction to the advertisement and a "distinct inconvenience" that people go to when using a smoke ball.
Lord Justice Bowen Bowen's opinion was more tightly structured in style, . Five main steps in his reasoning can be identified. First, he said that the contract was not too vague to be enforced, because it could be interpreted according to what ordinary people would understand by it. He differed slightly from Lindley on what time period one could contract flu and still have a claim (Lindley said a "reasonable time" after use, while Bowen said "while the smoke ball is used"), but this was not a crucial point, because the fact was that Carlill got flu while using the smoke ball. Second, like Lindley, Bowen said that the advert was not mere puff because £1000 was deposited in the bank to pay rewards. Third, he said that although an offer was made to the whole world, the contract was not with the whole world. Therefore, it was not an absurd basis for a contract, because only the people who used it would bind the company. Fourth, he said that communication is not necessary to accept the terms of an offer; conduct is and should be sufficient. Fifth, good consideration was clearly given by Carlill because she went to the "inconvenience" of using it, and the company got the benefit of extra sales.
Lord Justice Smith A L Smith's judgment was more general and concurred with both Lindley and Bowen's decisions.
Significance Carlill is significant for two areas of law: the law of contract, and the doctrine of puffery. Both areas have impacted advertising, and the problem of medical quackery.
Law of contract
Carlill is frequently cited as a leading case in the common law of contract, particularly where unilateral contracts are concerned.
It provides an excellent study of the basic principles of contract and how they relate to everyday life. The case remains good law. It still binds the lower courts of England and Wales and is cited by judges with approval.e.g. Soulsbury v Soulsbury Fam 1, 49 Bailii; Longmore applied the concept of unilateral contract in his judgement: "Once the promisee acts on the promise by inhaling the smoke ball, by starting the walk to York or (as here) by not suing for the maintenance to which she was entitled, the promisor cannot revoke or withdraw his offer. But there is no obligation on the promisee to continue to inhale, to walk the whole way to York or to refrain from suing. It is just that if she inhales no more, gives up the walk to York or does sue for her maintenance, she is not entitled to claim the promised sum." However, in addition to the contractual remedy afforded to users, the same facts would give rise to a number of additional statutory remedies and punishments were an individual to place an advert in the same terms today.
Firstly, misleading advertising is a criminal offence. Under the Consumer Protection from Unfair Trading Regulations2008/1277 Consumer Protection from Unfair Trading Regulations (secondary legislation, passed under the European Communities Act 1972), regulation 5 states that a commercial practice is misleading...
"if it contains false information and is therefore untruthful... or if it or its overall presentation in any way deceives or is likely to deceive the average consumer... even if the information is factually correct"
...in relation to a long list of actions and omissions by sellers. Misleading practices are unfair (r 3) and unfair practices are prohibited (r 4). They are also criminal offences (rr 8–18) and overseen by stringent enforcement mechanisms (rr 19–27).This was formally governed under the Consumer Protection Act 1987, s 20(1) Sellers still have a defence of legitimate "puffery", or that their representations could not be taken seriously (e.g. "this washing powder makes your clothes whiter than white!").
Secondly, although it was not discussed in the case, there was evidence at the time that using the smoke ball actually made people more vulnerable to the flu (carbolic acid was put on the poisons register in 1900). The General Product Safety Regulations2005/1803 which are part of a European Union wide consumer protection regime (Directive 2001/95/ECDirective 2001/95/EC of the European Parliament and of the Council of 3 December 2001 on general product safety) again provide criminal penalties for unsafe products.
Thirdly, the Consumer Protection Act 1987 (which is also part of EU wide regulation under Directive 85/374/EECCouncil Directive 85/374/EEC of 25 July 1985 on the approximation of the laws, regulations and administrative provisions of the Member States concerning liability for defective products) creates a statutory tort of strict liability for defective products that cause any kind of personal injury or death, or damage over £100. This is the primary method for individuals to get compensation for any loss resulting from products. Similar regimes for product liability have developed around the world through statute and tort law since the early twentieth century, one of the leading cases being Donoghue v Stevenson.
Fourthly, under the Enterprise Act 2002, s 8, as in most developed countries, industry members form a trade associations. Businesses are expected to collectively regulate one another by drawing up Codes of Practice and have mechanisms for enforcement before tort or criminal law does.
Viewed with a modern eye, many have argued that Carlill should be seen as redolent of another era, not a foundational case in the law of contract. For instance, Professor Hugh Collins writes the following.