The essential elements of a valid contract: QCE Legal Studies
“The essential elements of a valid contract, including offer, acceptance, consideration, intention and capacity”
A legally binding contract requires five essential elements: offer, acceptance, consideration, intention to create legal relations, and capacity. An offer must be distinguished from an invitation to treat (Boots case). Acceptance must mirror the offer; a counter-offer destroys it (Hyde v Wrench). Consideration must be sufficient but need not be adequate. Social and domestic agreements are presumed not to be binding (Balfour v Balfour). Contract law in Australia is mostly common law, supplemented by the Australian Consumer Law.
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What this dot point is asking
QCAA wants you to know what turns an everyday agreement into a legally enforceable contract: the essential elements that must all be present, and the common-law cases that define them. Contract law is mostly common law in Australia rather than codified. Expect a 3-5 mark short response in IA2.
The answer
The five essential elements
For a legally binding contract to exist, five elements must be present.
- 1. Offer
- A clear proposal made by one party (the offeror) to another (the offeree), capable of being accepted. An offer must be distinguished from an invitation to treat, which is merely an invitation for others to make offers. Goods displayed in a shop window or on a shelf are an invitation to treat, not an offer (Pharmaceutical Society of Great Britain v Boots Cash Chemists [1953] 1 QB 401). Advertisements are usually invitations to treat, but can be offers where they promise something specific in return for an act (Carlill v Carbolic Smoke Ball Co [1893] 1 QB 256).
- 2. Acceptance
- Unqualified agreement to all the terms of the offer. Acceptance must be communicated to the offeror and must mirror the offer. A response that changes the terms is a counter-offer, which destroys the original offer (Hyde v Wrench (1840) 49 ER 132). The postal acceptance rule can apply where post is a reasonable means of acceptance.
- 3. Consideration
- Something of value exchanged by each party (the "price" of the promise). Consideration must be sufficient but need not be adequate (the courts do not assess whether the bargain was a good one). Past consideration is generally not valid consideration.
- 4. Intention to create legal relations
- The parties must intend the agreement to be legally binding. There is a rebuttable presumption that commercial agreements are intended to be binding, and a rebuttable presumption that purely social or domestic agreements are not (Balfour v Balfour [1919] 2 KB 571).
- 5. Capacity
- The parties must have legal capacity to contract. Certain categories of person have limited capacity, including minors, people who lack mental capacity, and intoxicated persons. Contracts with minors are generally voidable, except for contracts for necessaries.
Genuine consent
Even where the five elements are present, a contract may be challenged where consent was not genuine, for example because of misrepresentation, mistake, duress, or undue influence. The Australian Consumer Law (Schedule 2 to the Competition and Consumer Act 2010 (Cth)) also prohibits misleading or deceptive conduct (s 18) and unconscionable conduct, which can affect the enforceability of consumer contracts.
Legality
The purpose of the contract must be lawful. A contract to do something illegal or contrary to public policy is unenforceable.
Express and implied terms
The terms of a contract may be express (stated by the parties) or implied (read in by law, custom or to give the contract business efficacy). Terms are also classified as conditions (essential terms), warranties (minor terms), or intermediate terms, which affects the remedies available for breach.
Discharge and breach
A contract may be discharged by performance, agreement, frustration, or breach. A breach occurs where a party fails to perform an obligation. The innocent party may sue for damages, and where a condition is breached, may also terminate the contract.
An invitation to treat is an indication that a person is willing to receive offers. It is not itself an offer. A shop display or advertisement is usually an invitation to treat, so the customer makes the offer and the seller chooses whether to accept it.
A common Unit 2 task gives an agreement and asks whether it is a binding contract. Work through it in steps.
Step 1: Find the offer
Identify a clear offer and distinguish it from an invitation to treat (a shop display, an advertisement).
Step 2: Find acceptance
Check that the offer was accepted on its terms and communicated.
Step 3: Check consideration
Confirm each party gave something of value (a benefit or detriment).
Step 4: Check intention and capacity
Confirm the parties intended legal relations (presumed in commercial, rebuttable in social agreements) and had capacity.
Step 5: Conclude on validity
State whether all elements are present, and if not, which missing element prevents formation.
- Saying a shop display is an offer
- Goods on display are usually an invitation to treat (Boots case). The customer makes the offer at the counter.
- Confusing consideration with a fair price
- Consideration must be sufficient (have some value in law) but need not be adequate. The courts do not assess whether the deal was a good bargain.
- Forgetting intention to create legal relations
- A social or domestic agreement is presumed not to be legally binding (Balfour v Balfour). The presumption can be rebutted by evidence.
- Treating a counter-offer as acceptance
- A counter-offer rejects and destroys the original offer (Hyde v Wrench). It cannot later be accepted unless renewed.
Examples in context
Example 1. A car sale advertised online. A seller lists a used car for sale on an online marketplace. The listing is an invitation to treat. A buyer who offers the asking price is making the offer; the contract is formed only when the seller accepts. If the seller responds by asking for a higher price, that is a counter-offer, and the original offer is gone unless renewed.
Example 2. A family promise that is not binding. A parent promises to pay an adult child an allowance while the child studies. When the parent stops paying, the child cannot sue for breach of contract, because the agreement is presumed to be a domestic arrangement with no intention to create legal relations (Balfour v Balfour [1919] 2 KB 571), and there is no contrary evidence to rebut the presumption.
Try this
Q1. List the five essential elements of a valid contract. [5 marks]
- Cue. Offer; acceptance; consideration; intention to create legal relations; capacity.
Q2. Distinguish between an offer and an invitation to treat, using a case to support your answer. [3 marks]
- Cue. An offer can be accepted to form a contract; an invitation to treat merely invites offers. A shop display is an invitation to treat (Pharmaceutical Society of Great Britain v Boots Cash Chemists [1953] 1 QB 401).
Q3. Explain how the presumption about intention to create legal relations differs between commercial and domestic agreements. [4 marks]
- Cue. Commercial agreements are presumed binding; social and domestic agreements are presumed not binding (Balfour v Balfour [1919] 2 KB 571). Both presumptions are rebuttable by evidence.
Exam-style questions
Questions in the style of QCAA exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
Practice5 marksExplain the essential elements required to form a valid contract, with a leading case for one element.Show worked answer →
A QCAA Paper 1 explain response needs all the elements and supporting authority.
- Offer and acceptance
- A clear offer (distinguished from an invitation to treat, Pharmaceutical Society of Great Britain v Boots) accepted on its terms.
- Consideration
- Each party must give something of value (a benefit or detriment).
- Intention
- The parties must intend to create legal relations (presumed in commercial dealings).
- Capacity
- The parties must have legal capacity (not minors for some contracts, not mentally incapacitated).
Markers reward all elements named with at least one leading case and the offer-versus-invitation-to-treat distinction.
Practice7 marksAnalyse, using a hypothetical scenario, whether a valid contract has been formed, and evaluate whether one party can enforce it.Show worked answer →
A QCAA Paper 1 analyse and evaluate response applies the elements to facts.
- Apply each element
- Work through offer, acceptance, consideration, intention and capacity against the scenario facts, flagging any that fail (a mere invitation to treat, no consideration, no intention in a social agreement).
- Identify the defect
- Pinpoint any missing element that prevents formation.
- Evaluate enforceability
- Conclude whether a binding contract exists and can be enforced, and what remedy would follow a breach. Markers reward applying each element to the facts and a reasoned conclusion.