Invitation to treat (or invitation to bargain in the United States) is a contract law term. It comes from the Latin phrase invitatio ad offerendum and means an "inviting an offer". Or as Andy Burrows writes, an invitaton to treat is
"an expression of willingness to negotiate. A person making an invitation to treat does not intend to be bound as soon as it is accepted by the person to whom the statement is addressed."
Contract lawyers distinguish this from a binding offer, which can be accepted to form a contract (subject to other conditions being met). The distinction between an offer and invitation to treat is best understood through the categories that the courts create. Invitations to treat include the display of goods; the advertisement of a price or an auction; and an invitation for tenders (or competitive bids). There may however be statutory or complementary obligations, so consumer protection laws prohibit misleading advertising and at auctions without reserve there is always a duty to sell to the highest bona fide bidder. But the general rule is that unlike an actual offer, an invitation to treat is not binding. The "inviter" can change his or her mind.
|Part of the common law series|
acceptance · Mailbox rule
Mirror image rule · Invitation to treat
Firm offer · Consideration
|Defenses against formation|
Duress · Undue influence
Illusory promise · Statute of frauds
Non est factum
Contract of adhesion
|Excuses for non-performance|
|Mistake · Misrepresentation
Frustration of purpose · Impossibility
Impracticability · Illegality
Unclean hands · Unconscionability
Accord and satisfaction
|Rights of third parties|
Assignment · Delegation
Novation · Third party beneficiary
|Breach of contract|
|Anticipatory repudiation · Cover
Exclusion clause · Efficient breach
Penal damages · Rescission
|Related areas of law|
|Conflict of laws · Commercial law|
|Other common law areas|
|Tort law · Property law
Wills, trusts and estates
Criminal law · Evidence
The clearest example of an invitation to treat is a tender (or bidding in the U.S.) process. This was illustrated in the case of Spencer v Harding (1870) LR 5 CP 561, where the defendants offered to sell by tender their stock and the court held that they had not undertaken to sell to the person who made the highest tender, but were inviting offers which they could then accept or reject as they saw appropriate. In certain circumstances though, an invitation for tenders may be an offer. The clearest example of this was seen in Harvela Investments Ltd v Royal Trust of Canada (CI) Ltd  AC 207, where the defendants had made it clear that they were going to accept the highest tender; the court held that this was an offer which was accepted by the person who made the highest tender and that the defendants were in breach of contract by not doing so.
An auction may be more ambiguous. Generally an auction may be seen as an invitation to treat, with the property owner asking for offers of a certain amount and then selecting which to accept as illustrated in Payne v Cave (1789) 3 TR 148. However, if it is stated by the owner that there is no reserve price or that there is a reserve price beyond which offers will be accepted then the auction is most likely a contractual offer which is accepted by the highest bidder; this was affirmed in the Appellate court in Barry v. Davies  1 WLR 1962.
A shop owner displaying their goods for sale is generally making an invitation to treat ( Pharmaceutical Society of Great Britain v Boots Cash Chemists (Southern) Ltd  1 QB 401). They are not obliged to sell the goods to anyone who is willing to pay for them, even if additional signage such as "special offer" accompanies the display of the goods. (But see bait and switch.) This distinction was legally relevant in Fisher v Bell  1 QB 394, where it was held that displaying a flicknife for sale in a shop did not contravene legislation which prohibited offering for sale such a weapon. The distinction also means that if a shop mistakenly displays an item for sale at a very low price it is not obliged to sell it for that amount .
Generally, advertisements are invitations to treat, so the person advertising is not compelled to sell to every customer. In Partridge v Crittenden  1 WLR 1204, it was held that where the appellant advertised to sell wild birds, was not offering to sell them. Lord Parker CJ commented that it did not make "business sense" for advertisements to be offers, as the person making the advertisement may find himself in a situation where he would be contractually obliged to sell more goods than he actually owned. In certain circumstances however, an advertisement can be an offer, a well known example being the case of Carlill v Carbolic Smoke Ball Company  1 QB 256, where it was held that the defendants, who advertised that they would pay anyone who used their product in the prescribed manner and caught influenza £100 and said that they had deposited £1,000 in the bank to show their good faith, has made an offer to the whole world and were contractually obliged to pay £100 to whoever accepted it by performing the requested acts.