Canadian Contract Law: A Complete Guide for Businesses

1. Offer

A clear, definite proposal by one party (the offeror) to enter into a contract on specified terms. The offer must be communicated to the other party (the offeree) and must demonstrate an intention to be bound if accepted. An offer remains open until accepted, rejected, countered, revoked, or it expires. Advertisements are generally considered invitations to treat — not offers — unless they contain unequivocal terms (e.g., a reward offer).

2. Acceptance

An unequivocal agreement to the terms of the offer. Acceptance must mirror the offer exactly — any modification is a counter-offer, not acceptance (the “mirror image” rule). Acceptance can be communicated by words, actions, or — in limited circumstances — silence (e.g., where the parties have an established course of dealing). In Canada, the “postal acceptance rule” still applies: acceptance by mail is effective when posted, not when received.

3. Consideration

Something of value exchanged between the parties — the “price” of the promise. Consideration can be money, goods, services, a promise to do something, or a promise to refrain from doing something. It must be present or future — past consideration (something already done before the contract) is generally not valid in Canada. The consideration does not need to be adequate (fair) — courts will not assess whether the deal is balanced — but it must be sufficient (have some legal value). A gift or gratuitous promise is not enforceable without consideration (unless under seal).

4. Intention to Create Legal Relations

Both parties must intend the agreement to have legal consequences. In commercial/business agreements, this intention is presumed. In social and domestic agreements (between friends or family), there is a presumption against legal intention — the party seeking enforcement must prove otherwise. This is why family loan agreements and family business arrangements should always be in writing.

5. Capacity

Both parties must have the legal capacity to enter into a contract. This means they must be of legal age (18 in most provinces; 19 in BC, New Brunswick, Nova Scotia, Newfoundland, and the territories), mentally competent, and not under the influence of drugs or alcohol to the extent that they cannot understand the nature of the contract. Contracts with minors are generally voidable at the minor’s option (except for necessities). A power of attorney may grant someone capacity to contract on behalf of another person.

6. Legality

The contract’s purpose and subject matter must be lawful. A contract for illegal goods, services, or activities is void and unenforceable. This includes contracts that violate federal or provincial statutes (e.g., a loan agreement with an interest rate exceeding the criminal rate), contracts to commit a crime, and contracts that violate public policy.

7. Certainty of Terms

The essential terms of the contract must be clear and definite — the parties, the subject matter, the price (or a mechanism to determine it), and the obligations of each party. A contract that is too vague or ambiguous for a court to determine the parties’ obligations is unenforceable. “Agreements to agree” are generally not enforceable in Canada, though they may create a duty to negotiate in good faith.

Duty of Honest Performance

Parties must not lie to or knowingly mislead the other party about matters directly linked to the contract. This does not require disclosure of all information — only that what you do say must be true. Applies to all contracts in common law Canada.

Duty to Negotiate in Good Faith

Where parties have entered into a pre-contractual relationship of reliance (e.g., through a letter of intent), they may owe each other a duty to negotiate in good faith — not to walk away arbitrarily after inducing reliance. This does not guarantee a deal will be reached.

Service Agreements — Contracts for professional services, consulting, and contractor engagements.

Share Purchase Agreements — Buying or selling shares in a corporation (M&A).

Asset Purchase Agreements — Buying specific business assets rather than shares.

Partnership Agreements — Contracts between partners governing a business partnership.

Non-Disclosure Agreements — Protecting confidential information from unauthorized disclosure.

Non-Compete Agreements — Restricting competition after employment or business sale.

Commercial Leases — Contracts for renting commercial property (office, retail, industrial).

Licensing Agreements — Granting rights to use intellectual property, technology, or brands.

Loan Agreements — Contracts for lending and borrowing money with defined repayment terms.

EULAs — Software licensing contracts between developers and end users.

Common Law (All Provinces Except Quebec)

Judge-made law based on precedent (court decisions).

Requires consideration for a contract to be enforceable.

Good faith duty established by Bhasin v. Hrynew (2014).

Statute of Frauds requires certain contracts to be in writing (land transfers, guarantees).

Civil Law (Quebec)

Codified in the Civil Code of Quebec (CCQ).

Concept of “cause” replaces consideration — a contract needs a valid reason, not necessarily an exchange of value.

Good faith has been a foundational principle since the CCQ’s adoption (art. 1375).

Lesion (grossly unfair terms) can void a contract — not available in common law except for unconscionability.

Misrepresentation: A false statement of fact that induced the other party to enter the contract. Can be innocent, negligent, or fraudulent — each with different remedies.

Duress: A party was coerced into signing — through threats of violence, economic pressure, or other illegitimate means. The contract is voidable at the coerced party’s option.

Undue influence: One party exploited a position of trust or power over the other — common in relationships between professionals and clients, elderly parents and children, or employers and vulnerable employees.

Unconscionability: The contract is so one-sided and unfair — resulting from an inequality of bargaining power — that enforcing it would be unjust. Canadian courts apply a two-part test: was there inequality of bargaining power, and did it result in an improvident bargain?

Mistake: Common mistake (both parties share the same mistaken belief about a fundamental fact), mutual mistake (both are mistaken but about different things), or unilateral mistake (one party is mistaken and the other knew or should have known).

Frustration: An unforeseen event — beyond the parties’ control — makes it impossible or radically different to perform the contract. The contract is automatically discharged. Not the same as a contract becoming more expensive or less profitable.

No written contract. Oral contracts are generally enforceable — but proving their terms in court is extremely difficult. Always put agreements in writing, especially for significant transactions. The cost of drafting is a fraction of the cost of litigating an oral agreement gone wrong.

Using templates from other jurisdictions. A U.S. or U.K. contract template may reference laws that do not apply in Canada, use terminology that has different legal meanings, or omit Canadian-specific requirements (PIPEDA, provincial consumer protection, HST/GST). Always use a template drafted for Canadian law.

Insufficient consideration for contract amendments. Modifying an existing contract requires fresh consideration — without it, the amendment may be unenforceable. This is a frequent issue with employment contract changes (e.g., adding a non-compete after the employee has already started working). Provide something new of value when amending contracts.

Ignoring limitation periods. Every province has a limitation period within which you must commence a legal action for breach of contract — typically 2 years from when you knew (or should have known) about the breach. Miss the deadline, and your claim is barred regardless of its merits.

No dispute resolution clause. Without a dispute resolution clause, disagreements go straight to court — the most expensive and time-consuming option. Include an escalation path: negotiation → mediation → arbitration, with specified timelines, governing law, and venue.

Contracts for the sale of land — Any agreement that conveys, transfers, or creates an interest in real property must be in writing and signed by the party to be charged. This includes commercial leases, mortgage agreements, and agreements for the purchase and sale of real property.

Guarantees — A promise to pay another person’s debt (a guarantee or indemnity) must be in writing. This is common in business lending, where a director personally guarantees a corporate loan agreement or general security agreement.

Contracts not performable within one year — An agreement that by its terms cannot be fully performed within one year of its formation must be in writing. Note: if there is any possibility the contract could be completed within one year, the Statute of Frauds does not apply.

Sale of goods above a threshold — In some provinces, the Sale of Goods Act requires contracts for the sale of goods above a specified value (e.g., $50 in Ontario) to be evidenced in writing or by part performance.