Authored By: Walter Gabriel Matthew
Rivers State University
CASE TITLE & CITATION
Carlill v. Carbolic Smoke Ball Company1.
Key Citations (Bluebook 20th ed.)
COURT NAME & BENCH COURT:
Court of Appeal (Civil Division), England and Wales
Bench: Lindley L.J., Bowen L.J., and A.L. Smith L.J.
Bench Type: Division Bench (Three Judges)
DATE OF JUDGEMENT
Judgement delivered on December 7, 1892 (reported in 1893).
PARTIES INVOLVED
Appellant (Defendant): Carbolic Smoke Ball Company, a firm engaged in the manufacture and sale of a medicinal product known as the “Smoke Ball”, claimed to prevent influenza.
Respondent (Plaintiff): Mrs Louisa Elizabeth Carlill, a consumer who purchased and used the Smoke Ball as directed but subsequently contracted influenza and sought to recover the reward promised in the company’s advertisement.
FACTS OF THE CASE
During the influenza epidemic of the 1890s, the Carbolic Smoke Ball Company published an advertisement in several newspapers claiming that its product would prevent influenza if used properly. The advertisement stated that £100 would be paid to any person who contracted influenza after using the ball as directed. To show seriousness, the company claimed to have deposited £1,000 in the Alliance Bank for the purpose of paying such rewards.
Mrs Carlill, relying on this advertisement, purchased the Smoke Ball and used it exactly as instructed for nearly two months. Despite this, she contracted influenza and claimed the £100 reward. The company refused, asserting that the advertisement was a mere sales puff with no intent to form legal relations.
Mrs Carlill filed a suit, and the lower court ruled in her favour. The company appealed, arguing that no valid contract existed because the advertisement was not an offer but an invitation to treat, and because no notice of acceptance had been given.
ISSUES RAISED
The Court of Appeal considered the following legal issues:
➢ Whether the advertisement constituted a binding offer or was merely an invitation to treat.
➢ Whether Mrs Carlill’s performance of the stated conditions amounted to a valid acceptance.
➢ Whether consideration existed to support a legally enforceable contract.
➢ Whether there was a genuine intention to create legal relations.
➢ Whether the terms of the alleged contract were too vague or uncertain to be enforceable.
ARGUMENTS OF THE PARTIES
Arguments for the Appellant (Carbolic Smoke Ball Co.):
➢ The advertisement was a mere puff, lacking contractual intent, as such promotional language is common in commerce.
➢ There was no offer, only an invitation to treat, as it was addressed to the public at large without identifying any specific offeree.
➢ There was no acceptance communicated by Mrs Carlill, a necessary element for contract formation.
➢ The supposed contract lacked consideration, since the plaintiff’s use of the Smoke Ball did not confer any measurable benefit upon the company.
➢ The terms were too indefinite; for instance, no time limit for contracting influenza was specified.
Arguments for the Respondent (Mrs Carlill):
➢ The advertisement’s language, especially the £1,000 bank deposit, clearly demonstrated serious intent to be legally bound.
➢ The offer was unilateral, made to anyone who performed the specified conditions.
➢ Acceptance occurred through performance (using the Smoke Ball as directed), and no separate communication was required.
➢ Consideration existed because Mrs Carlill incurred inconvenience, expense, and potential risk of harm by relying on the company’s promise.
➢ The contract was certain and complete, with conditions clearly laid out in the advertisement.
JUDGEMENT / FINAL DECISION
The Court of Appeal unanimously dismissed the company’s appeal and upheld the lower court’s judgement in favour of Mrs Carlill, confirming that a binding and enforceable contract existed between her and the Carbolic Smoke Ball Company.
All three Lords Justices — Lindley L.J., Bowen L.J., and A.L. Smith L.J. — delivered concurring judgements, agreeing entirely on both reasoning and result. There was no dissent in the case, which underscores the legal clarity and persuasive strength of the principles established.
Lindley L.J., delivering the lead judgement, emphasised that the company’s advertisement was not a mere puff but a serious and definite promise to the public. The deposit of £1,000 in the bank demonstrated genuine intention to create legal relations, negating any claim that the offer was a joke or promotional exaggeration. He further explained that the offer was unilateral, requiring no notification of acceptance because the company impliedly waived that requirement when it invited performance as the mode of acceptance.
Bowen L.J. concurred and elaborated on the doctrine of objective intention, asserting that the court’s role is not to determine what the parties privately meant but how their words and actions would appear to a reasonable person. He held that the advertisement was an offer to the world,
definite in its terms, and capable of acceptance by anyone who performed the conditions. Bowen L.J. clarified that a contract can be formed without direct communication between the parties if the nature of the offer dispenses with such formality—a principle foundational to unilateral contracts.
A.L. Smith L.J., concurring with both, added that the consideration supplied by Mrs Carlill was sufficient and valuable in law. Her reliance on the company’s promise, her effort and inconvenience in using the Smoke Ball, and her exposure to potential harm or futility in so doing, collectively satisfied the requirement of consideration. He reiterated that the company’s deposit of money in the bank was powerful proof of its intent to be bound and that such advertisements, though made to the public, could indeed give rise to enforceable legal obligations.
Collectively, the Court of Appeal held that:
- The advertisement constituted a unilateral offer to the public, capable of acceptance by anyone who fulfilled the stated conditions.
- Mrs Carlill accepted the offer through her actions — by purchasing and using the Smoke Ball according to the instructions — thereby forming a valid contract.
- The deposit of £1,000 in the bank evidenced serious contractual intent, showing the company’s readiness to honour its promise.
- Consideration existed in the form of Mrs Carlill’s inconvenience, expenditure, and reliance on the company’s promise.
Thus, the Court concluded that all the essential elements of a contract — offer, acceptance, consideration, and intention — were satisfied. There was, therefore, no uncertainty or lack of consensus ad idem. The appeal was accordingly dismissed, and judgement was entered for the respondent, Mrs Carlill, entitling her to the £100 reward.
The unanimity of the decision made Carlill v. Carbolic Smoke Ball Co2. is a landmark precedent. It clarified the formation of unilateral contracts and the boundaries of intention to create legal relations in English contract law. The absence of dissent also strengthened the case’s authority, ensuring its endurance as one of the most cited decisions in both English and Commonwealth jurisprudence, including Nigeria.
LEGAL REASONING / RATIO DECIDENDI
The Court, through the judgements of Lindley L.J., Bowen L.J., and A.L. Smith L.J., established several enduring principles of contract law:
- Unilateral Offer and Acceptance by Conduct: The advertisement was an offer to the world that could be accepted by anyone who fulfilled the stated conditions. No prior notification of acceptance was necessary. As Bowen L.J. noted, the company “must be taken to have waived the necessity of notification of acceptance” by the nature of its offer.
- Intention to Create Legal Relations: The company’s public statement that it had deposited £1,000 with a bank served as strong evidence of intention to be legally bound, distinguishing it from mere advertising exaggeration.
- Consideration: The court held that Mrs Carlill’s inconvenience and time spent in using the product constituted sufficient consideration. It was immaterial that the company gained no direct benefit, as consideration may consist of detriment to the promisee.
- Certainty of Terms: The advertisement was sufficiently definite: it specified the reward amount, the condition for earning it, and the method of use. Hence, it was not void for uncertainty.
- Objective Interpretation of Intention: The court reaffirmed the objective test for determining contractual intent: it is not what the parties subjectively thought but how their words and actions would be understood by a reasonable person.
The court drew upon principles later echoed in Bowerman v. Association of British Travel Agents Ltd.3, reaffirming that unilateral offers made to the public can bind the offeror upon fulfillment of conditions. The case has become the foundation of modern contract law, particularly the doctrines of offer, acceptance, and intention to create legal relations. It has been cited across jurisdictions, including Nigeria, as persuasive authority on contractual intent and unilateral obligations.
CONCLUSION / OBSERVATIONS
Carlill v. Carbolic Smoke Ball Co4. is a cornerstone case that illustrates how ordinary commercial promises can acquire legal significance when backed by intention, clarity, and performance. It marked a turning point in contract law, proving that public advertisements can constitute binding offers when serious intent is shown.
In Nigerian jurisprudence, the principles in Carlill resonate with domestic law. Under the Evidence Act 2011 as amended 2023 (particularly Section 93) and common law doctrines adopted through received English law, similar reasoning applies. The Supreme Court of Nigeria, in A.G. Bendel State v. Aideyan5, emphasised that mutual consent and intention are essential for valid contracts — echoing Carlill’s objective test for intent.
Today, Carlill continues to influence the legal recognition of digital and online contracts, where offers are made to the public through websites or apps and acceptance occurs by conduct (e.g., clicking “I agree”). The reasoning also underpins modern developments in smart contracts on blockchain systems, which execute automatically upon fulfilment of coded terms — a digital echo of Mrs Carlill’s simple act of performance.
Thus, this case remains not merely a relic of Victorian law but a living authority that bridges 19th– century principles with 21st-century digital reality.
Reference(S):
1[1893] 1 Q.B. 256 (C.A.).
2Supra
3[1996] C.L.C. 451
4Supra
5(1989) 4 N.W.L.R. (Pt. 118) 646

