Suing for Breach of Contract in Ontario

Contracts are the backbone of commerce and everyday life. When someone breaks a promise that was legally binding — a supplier fails to deliver, a service provider walks off the job, a buyer refuses to close — you may have a claim for breach of contract. In Ontario, contract law gives injured parties real remedies: financial compensation, and in limited circumstances, a court order requiring the other side to actually perform what they promised.

Understanding the framework helps you know whether you have a claim, what you might recover, and what you need to prove.

What Is a Breach of Contract?

A contract is a legally enforceable agreement. For a contract to exist, there must generally be:

• Offer — one party proposes specific terms;
• Acceptance — the other party agrees to those terms;
• Consideration — something of value flows both ways (money, a promise, a service);
• Intention to create legal relations — the parties intended the agreement to be binding; and
• Certainty of terms — the agreement is clear enough to be enforced.

A breach occurs when one party fails to perform a contractual obligation without a lawful excuse. Breaches come in different forms:

• Failure to pay — the most common; goods or services delivered, invoice ignored.
• Failure to deliver or perform — a vendor who takes a deposit and vanishes; a contractor who does partial work and abandons the job.
• Defective performance — work completed, but not to the standard required by the contract.
• Anticipatory breach — one party clearly signals, before the performance date, that they will not be performing. This can entitle the other party to treat the contract as ended immediately and sue without waiting.

Does the Contract Have to Be in Writing?

Not always. Many oral contracts are fully enforceable in Ontario. However, certain contracts must be in writing to be legally valid — most notably, contracts for the sale of land and certain consumer agreements. Even where writing is not required for validity, a written contract is far easier to prove in court. An oral agreement often collapses into "your word against theirs."

Remedies for Breach of Contract

1. Damages (Financial Compensation)

The primary remedy for breach of contract is compensatory damages — money to put you in the position you would have been in had the contract been performed.

Expectation damages are the most common: the benefit you expected from the contract that you did not receive. If you paid $20,000 for a renovation and the contractor did $8,000 worth of work before abandoning the job, your expectation damages might include the cost to have another contractor complete the work, plus any additional cost above what you originally contracted for.

Consequential damages (also called special damages) cover losses beyond the immediate contract value — for example, lost profits your business suffered because the supplier failed to deliver on time. To recover consequential damages, those losses must have been reasonably foreseeable at the time the contract was made and must be proven with reasonable certainty.

Nominal damages are a small, symbolic award when a breach is proven but no real financial loss resulted. Courts can award them to vindicate your contractual rights.

Courts will not award damages that are too remote — losses that a reasonable person in the defendant's position could not have anticipated as a likely consequence of the breach.

2. Specific Performance

In exceptional circumstances, a court may order specific performance — requiring the party in breach to actually perform the contract. This remedy is rare in Ontario and is generally reserved for situations where money alone cannot adequately compensate the plaintiff.

The classic case is a contract for the sale of unique real estate: because no two properties are identical, a court may order the seller to complete the sale rather than simply awarding the buyer the financial difference. Specific performance is far less commonly granted for commercial goods or services where substitute performance is available.

3. Rescission and Restitution

Rescission unwinds the contract and returns the parties to where they started. It is available where there has been a fundamental breach, misrepresentation, or other vitiating factor. If rescission is granted, deposits and payments made must generally be returned.

Your Duty to Mitigate

Ontario law imposes a duty to mitigate on the party who suffers a breach. This means you are obliged to take reasonable steps to reduce your losses. You cannot sit back, let damages mount, and expect the other party to pay the full accumulated amount.

For example, if your contractor abandons a project, you should make reasonable efforts to hire a replacement promptly rather than leaving the work unfinished for months. A court will reduce your damages by the amount you could have avoided through reasonable mitigation.

Mitigation does not mean you must accept unreasonable terms or go to extreme lengths — it simply requires reasonable, commercially sensible action.

Proving Your Contract Claim

To succeed in a breach of contract action in Ontario, you must prove on a balance of probabilities (more likely than not) that:

1. A valid contract existed;
2. You performed your own obligations (or were ready to perform, or had a lawful excuse for not performing);
3. The defendant breached a term of the contract; and
4. You suffered a loss as a result of the breach.

Key Evidence to Gather

• The written contract itself, including any amendments, schedules, or attachments.
• Invoices, purchase orders, quotes, and statements of account.
• Emails, text messages, and letters — these often confirm the terms, record complaints, and show who said what and when.
• Photographs and videos documenting the state of work, delivered goods, or property.
• Receipts and estimates from third parties showing the cost to fix or complete the work.
• Any witnesses who can speak to what was agreed and what happened.

The stronger your documentary record, the stronger your case. Courts are skeptical of bare verbal assertions with nothing to back them up.

Small Claims vs. Superior Court

In Ontario, the venue for your claim depends on the amount in dispute. As of writing, Small Claims Court handles claims up to $35,000 (verify the current limit, as it is set by regulation). Claims exceeding that amount belong in the Superior Court of Justice, where the process is more formal, costs are higher, and legal representation becomes much more important.

For large commercial disputes — failed real estate deals, significant supply chain failures, multi-party construction contracts — the Superior Court's full procedural toolkit (examinations for discovery, documentary disclosure, expert evidence rules) is often necessary to build and present a compelling case.

Frequently asked questions