Келісімнің екі құрауы: ұсыныс және қабылдау

Two components of agreement

Offer and acceptance are generally recognized as essential requirements for the formation of a contract (together with other requirements such as consideration and legal capacity). Analysis of their operation is a traditional approach in contract law. This classical approach to contract formation has been modified by developments in the law of estoppel, misleading conduct, misrepresentation, unjust enrichment, and power of acceptance.

Treitel defines an offer as "an expression of willingness to contract on certain terms, made with the intention that it shall become binding as soon as it is accepted by the person to whom it is addressed", the "offeree". An offer is a statement of the terms on which the offeror is willing to be bound. The expression of an offer may take different forms, and which form is acceptable varies by jurisdiction. Offers may be presented in a letter, newspaper advertisement, fax, email verbally or even conduct, as long as it communicates the basis on which the offeror is prepared to contract. Traditionally the common law treated advertisements as being unable to contain offers, but that view is less forceful in jurisdictions today. Whether the two parties have reached agreement on the terms or whether a valid offer has been made is a legal question. In some jurisdictions, courts use criteria known as 'the objective test', which was explained in the leading English case of Smith v. Hughes. In Smith v. Hughes, the court emphasised that the important thing in determining whether there has been a valid offer is not the party's own (subjective) intentions but how a reasonable person would view the situation. The objective test has largely been superseded in the UK by the introduction of the Brussels Regime in combination with the Rome I Regulation. An offer can be the basis of a binding contract only if it contains the key terms of the contract. For example, in some jurisdictions, a minimum requirement for sale of goods contracts is the following four terms: delivery date, price, terms of payment that includes the date of payment, and a detailed description of the item on offer including a fair description of the condition or type of service. Other jurisdictions vary or eliminate these requirements. Unless the minimum requirements are met, an offer of sale is not classified by the courts as a legal offer but is instead seen as an advertisement. Under Dutch law an advertisement is in most cases an invitation to make an offer, rather than an offer. In line with the definition from Treitel above, to invite acceptance an offer must be serious. In this sense, an obvious joke cannot become the basis of an offer because the potential offeror lacks actual intent to enter into an exchange. For instance, in the famous case of Leonard v. Pepsico, Inc., depiction of a military aircraft offered in exchange for "Pepsi Points" was interpreted by a court as a joke. Despite having clear terms (7,000,000 Pepsi Points in exchange for one aircraft), the humorous elements of the commercial rendered that portion of the advertisement a joke rather than a serious offer. Whether a potential offer is serious is evaluated under an objective standard, independent of the subjective intent of the one making or accepting the offer. In the case of Lucy v. Zehmer, what one party believed were jests about selling a farm turned into a binding contract, based on the court's evaluation of the circumstance from the perspective of a reasonable observer. Similarly, in the case of Berry v. Gulf Coast Wings Inc., one party's offer of a "Toyota" for the winner of a contest was interpreted as requiring the offeror to provide a vehicle to the winner rather than a "Toy Yoda" doll from Star Wars, despite the assertion that the contest was based on a joke.

A unilateral contract is created when someone offers to do something "in return for" the performance of the act stipulated in the offer. In a unilateral contract, acceptance may not have to be communicated and can be accepted through conduct by performing the act. Nonetheless, the person performing the act must do it in reliance on the offer. A unilateral contract differs from a bilateral contract, where there is an exchange of promises between two parties. For example, if one party promises to buy a car and the other party promises to sell a car, that is a bilateral contract. The formation of a unilateral contract can be demonstrated in the English case Carlill v Carbolic Smoke Ball Co. an indication by the owner of property that he or she might be interested in selling at a certain price, for example, has been regarded as an invitation to treat. Similarly in the English case Gibson v Manchester City Council the words "may be prepared to sell" were held to be a notification of price and therefore not a distinct offer, though in another case concerning the same change of policy (Manchester City Council underwent a change of political control and stopped the sale of council houses to their tenants) Storer v. Manchester City Council, the court held that an agreement was completed by the tenant's signing and returning the agreement to purchase, as the language of the agreement had been sufficiently explicit and the signature on behalf of the council a mere formality to be completed. Statements of invitation are only intended to solicit offers from people and are not intended to result in any immediate binding obligation. The courts have tended to take a consistent approach to the identification of invitations to treat, as compared with offer and acceptance, in common transactions. The display of goods for sale, whether in a shop window or on the shelves of a self service store, is ordinarily treated as an invitation to treat and not an offer. The holding of a public auction will also usually be regarded as an invitation to treat. Auctions are, however, a special case generally. The rule is that the bidder is making an offer to buy and the auctioneer accepts this in whatever manner is customary, usually the fall of the hammer. A bidder may withdraw his or her bid at any time before the fall of the hammer, but any bid in any event lapses as an offer on the making of a higher bid, so that if a higher bid is made, then withdrawn before the fall of the hammer, the auctioneer cannot then purport to accept the previous highest bid. If an auction is without reserve then, whilst there is no contract of sale between the owner of the goods and the highest bidder (because the placing of goods in the auction is an invitation to treat), there is a collateral contract between the auctioneer and the highest bidder that the auction will be held without reserve (i. e., that the highest bid, however low, will be accepted). The U. S. Uniform Commercial Code provides that in an auction without reserve the goods may not be withdrawn once they have been put up.

An offeror may revoke an offer before it has been accepted, but the revocation must be communicated to the offeree (although not necessarily by the offeror). If the offer was made to the entire world, such as in Carlill's case,

If the offer is one that leads to a unilateral contract, the offer generally cannot be revoked once the offeree has begun performance.

Unaccepted offers to purchase are generally not recognised by courts for the purpose of proving the value of the proposed purchase. In the US case of Sharp v. United States (1903), a New Jersey landowner, Sharp, argued that the value of his land which had been taken by the government for fortification and defence purposes had been underestimated, and he sought to put forward examples of "different offers he had received to purchase the property for hotel, residential, or amusement purposes, or for a ferry, or a railroad terminal, or to lease the property for hotel purposes". The trial court (the District Court of New Jersey), the Court of Appeals for the Third Circuit and the Supreme Court all affirmed that such evidence was to be rejected, citing evidence from a number of previous cases which had established the same principle. Offers to purchase are considered to suffer "inherent unreliability for this purpose".

A promise or act on the part of an offeree indicating a willingness to be bound by the terms and conditions contained in an offer. Also, the acknowledgment of the drawee that binds the drawee to the terms of a draft.

Acceptance is judged by an objective standard, based on the conduct of the offeree. (Some have argued that the old common law rule used a subjective perspective.) The requirement of an objective perspective is important in cases where a party claims that an offer was not accepted and seeks to take advantage of the performance of the other party. Here, we can apply the test of whether a reasonable bystander (a "fly on the wall") would have perceived that the party has impliedly accepted the offer by conduct.

Common law contracts are accepted under a "mirror image" rule. Under this rule, an acceptance must be an absolute and unqualified acceptance of all the terms of the offer. If there is any variation, even on an unimportant point, between the offer and the terms of its acceptance, there is no contract. In the United States, the Uniform Commercial Code provides for acceptance even when terms of the acceptance differ from terms of the offer. This might occur, for example, when a buyer's "Terms and Conditions" differ from a seller's "Terms and Conditions" yet both parties behave as if a contract exists. In this case, a complex series of rules known as "Battle of the Forms" evaluates what is included in the contract. These rules might require, for instance, that conflicting terms in the offer and acceptance are "knocked out" and replaced by default language provided in the Code. An acceptance is only contractually valid if the proposal to which response is made is an offer capable of acceptance. In an Appeal Court ruling in 2020, Sir John Chadwick, judge, accepted the argument put by the appellant in the case, drawing:

Often when two companies deal with each other in the course of business, they will use standard form contracts. Often these standard forms contain terms which conflict (e. g. both parties include a liability waiver in their form). The 'battle of the forms' refers to the resulting legal dispute arising where both parties accept that a legally binding contract exists, but disagree about whose standard terms apply. Such disputes may be resolved by reference to the 'last document rule', i. e. whichever business sent the last document, or 'fired the last shot' (often the seller's delivery note) is held to have issued the final offer and the buyer's organisation is held to have accepted the offer by signing the delivery note or simply accepting and using the delivered goods. In U. S. law, this principle is referred to as the last shot rule. Under English law, the question was raised in Butler Machine Tool Co Ltd v Ex Cell O Corporation (England) Ltd, as to which of the standard form contracts prevailed in the transaction. Lord Denning MR preferred the view that the documents were to be considered as a whole, and the important factor was finding the decisive document; on the other hand, Lawton and Bridge LJJ preferred traditional offer acceptance analysis, and considered that the last counter offer prior to the beginning of performance voided all preceding offers. The absence of any additional counter offer or refusal by the other party is understood as an implied acceptance. In Leicester Circuits Ltd. v. Coates Brothers plc (2002) and GHSP Incorporated v AB Electronic Ltd (2010) the English High Court has found that companies may have not agreed on any terms, and so the 'last document rule' may not apply. In the GHSP case, there was no situation where one company could have been said to have accepted the other's standard terms, as they remained in unresolved dispute. The court held that neither party's terms applied and therefore the contract was governed by the implied terms of the UK Sale of Goods Act 1979.

As a rule of convenience, if the offer is accepted by post, the contract comes into existence at the moment that the acceptance was posted. This rule only applies when, impliedly or explicitly, the parties have post in contemplation as a means of acceptance. It excludes contracts involving land, letters incorrectly addressed and instantaneous modes of communication. The relevance of this early 19th century rule to modern conditions, when many quicker means of communication are available has been questioned, but the rule remains good law for the time being.

In Australian law, there is a requirement that an acceptance is made in reliance or pursuance of an offer.

Generally death (or incapacity) of the offeror terminates the offer. This does not apply to option contracts, in which the there's a possibility in which the next of kin or an assigned friend of the offeror can take his or her place after death. The offer cannot be accepted if the offeree knows of the death of the offeror. In cases where the offeree accepts in ignorance of the death, the contract may still be valid, although this proposition depends on the nature of the offer. If the contract involves some characteristic personal to the offeror, the offer is destroyed by the death.

A contract will be formed (assuming the other requirements for a legally binding contract are met) when the parties give objective manifestation of an intent to form the contract. Because offer and acceptance are necessarily intertwined, in California (US), offer and acceptance are analyzed together as subelements of a single element, known either as consent of the parties or mutual assent. Under the Uniform Commercial Code, offer and acceptance are not essential, and the timing of contract formation need not be clear for a contract to exist. Scholars have pointed out that many contracts are not in fact formed by offer and acceptance, and they have critiqued and reanalyzed the doctrine.