Advertisements are usually invitations to treat, which allows sellers to refuse to sell products at prices mistakenly marked. Advertisements can also be considered offers in some specific cases. A proposal or an offer must be distinguished from an invitation to treat. It is provided in section 2(a) of the Contracts Act 1950 which states that a proposal is made when “one person signifies to another his willingness to do or abstain from doing something with a view to obtaining the assent to that other for such an act or abstinence”. A proposal can be accepted and it amounts to an agreement. If the agreement is breached, it can be a breached of contract. A proposal can either be made to a particular person or to the general public. The person who is making the offer is the offeror whereas the person who is accepting the offer is the offeree.
As for invitation to treat, the Contracts Act does not provide any provision respecting this aspect of contract. An invitation to treat is not a proposal but it is a preliminary communication between the parties at the stage of negotiation, for instance, a price display of goods with price tags in the self-service supermarket or an advertisement. This is applied in Pharmaceutical Society of Great Britain v Boots Cash Chemist Ltd [1953] 1 QB 401
HELD: that the display was only an invitation to treat and a proposal to buy was made when the customer placed the article in the basket and takes them to the cashier’s desk. Therefore, the shop owners had not made an unlawful sale. An invitation to treat cannot be accepted because it is not an offer therefore it does not