- Minor (or Partial) Breach A minor breach — sometimes called a partial breach — occurs when a party substantially performs their obligations but falls short in some way that does not go…
- Courts weigh a cluster of factors, and the analysis is fact-specific.
- Misclassifying a breach is a trap that catches even sophisticated business parties.
Not every broken promise is created equal. If a contractor finishes your renovation two days late but the work is perfect, you have likely suffered a breach of contract — but probably not one that lets you refuse to pay or tear up the agreement. If that same contractor abandons the project midway through and takes your deposit, the situation is entirely different.
This distinction — between a material breach and a minor breach — is one of the most practically important concepts in Ontario contract law. Get it wrong, and you may end up being the party held liable. This article explains how courts in Ontario draw the line, why it matters, and what your options are when a serious breach occurs.
Minor Breach vs. Material Breach: The Core Distinction
Minor (or Partial) Breach
A minor breach — sometimes called a partial breach — occurs when a party substantially performs their obligations but falls short in some way that does not go to the heart of the contract. The innocent party is entitled to sue for any actual loss caused by the shortfall, but they cannot treat the contract as ended. The contractual relationship continues; you still have to perform your own obligations.
Examples of what courts have treated as minor breaches include:
- Delivering goods a few days after the agreed date when time was not explicitly made "of the essence"
- Completing a service with small defects that can be repaired at modest cost
- Missing an administrative deadline that caused no material prejudice to the other side
Material (or Fundamental) Breach
A material breach — sometimes called a fundamental breach — goes to the root of the contract. It deprives the innocent party of substantially the whole benefit they were supposed to receive. When a material breach occurs, the innocent party faces a choice: accept the repudiation and terminate the contract, or affirm the contract and sue for damages while keeping it alive.
That choice is consequential and time-sensitive. Making the wrong call can shift legal liability from the breaching party to you.
How Ontario Courts Decide Whether a Breach Is Material
There is no bright-line rule. Courts weigh a cluster of factors, and the analysis is fact-specific. Key considerations include:
The extent of non-performance. How much of what was promised was actually delivered? A contractor who completes 90% of a renovation is in a very different position from one who completes 10%.
Whether the breach can be remedied. If the shortfall can be cured quickly and at reasonable cost, courts are more likely to treat it as minor. If the defect is permanent or the damage is done, the analysis shifts.
The importance of the breached term. Some contract terms are conditions — so central that breaching them automatically gives the other party the right to terminate. Others are warranties — important but not fundamental, breaching them gives rise to damages only. Courts look at the contract's wording, the surrounding circumstances, and the parties' intentions at the time of contracting.
Whether the innocent party received any benefit. If the breaching party's partial performance conferred real value, courts may find that full termination overreaches.
The consequences of the breach. Courts ask: does the breach deprive the innocent party of substantially what they bargained for? If yes, it is material.
Why the Distinction Matters So Much: The Risk of Getting It Wrong
Misclassifying a breach is a trap that catches even sophisticated business parties. Here is why it matters so much in practice.
If you terminate the contract in response to what turns out to be only a minor breach, you have committed your own breach — likely a material one. The other side can then sue you for damages arising from your wrongful termination. You have turned yourself from the victim into the defendant.
If you keep the contract alive in response to a material breach and continue performing your own obligations, you may be taken to have affirmed the contract, waiving your right to terminate based on that breach. You may still be able to sue for damages, but you have lost the right to walk away.
The sequencing matters too. Once you become aware of a material breach, you must make your election reasonably promptly. Delay can be treated as affirmation.
Terminating the Contract: What to Do and What to Avoid
If you believe you are facing a material breach, here is a general framework — though you should get legal advice before acting:
Step 1 — Document everything. Preserve the contract, all communications, evidence of the breach, and records of any losses you have suffered or are likely to suffer. Do not destroy anything, even material that seems unflattering to your position.
Step 2 — Review the contract terms. Look for termination clauses, notice requirements, and any dispute-resolution steps you must follow before terminating. Many commercial contracts require written notice of breach and a cure period before termination becomes available.
Step 3 — Assess materiality carefully. This is the step where legal advice is most valuable. The cost of a lawyer's opinion at this stage is almost always less than the cost of getting it wrong.
Step 4 — Communicate clearly if you terminate. Acceptance of a repudiation should be unambiguous. A muddled response — threatening to terminate while still performing — can muddy your legal position considerably.
Step 5 — Mitigate your losses. Once you have terminated, you are under a duty to take reasonable steps to limit your damages. Courts can reduce a damages award if you failed to mitigate when you reasonably could have.
A Word on Contractual Termination Clauses
Many commercial contracts include explicit termination rights — clauses that specify the circumstances in which a party may terminate, the notice required, and the consequences. These clauses do not replace the common-law right to terminate for material breach, but they often operate alongside it.
If your contract has a termination clause, read it carefully before acting. Terminating outside the scope of the clause — when only the clause-based right applies and not the common-law right — can expose you to liability.
Frequently asked questions
How do I know if a breach is material or minor before going to court?
There is no guaranteed answer in advance — courts make this determination based on all the facts. But the core question is this: did the breach deprive you of substantially the whole benefit the contract was supposed to give you? If yes, materiality is strongly arguable. If the breach is a partial failure that still left you with most of what you bargained for, a court may find it minor. A lawyer can give you an honest assessment of where your situation falls on that spectrum.
Can I still sue for damages if I affirm the contract after a material breach?
Yes. Affirming the contract means you are keeping it alive and expecting the other side to continue performing — but you do not lose the right to sue for damages caused by the breach. What you give up is the right to terminate based on that particular breach.
What if the contract says a certain term is a "condition"?
Courts take contractual labels seriously, but not as automatically decisive. A clause labelled a "condition" is strong evidence that the parties intended breach of that term to give rise to termination rights, but courts still look at the overall context and intentions of the parties.
Does a minor breach ever become material over time?
Yes. A series of minor breaches — persistent late deliveries, ongoing quality shortfalls — can collectively amount to a repudiation of the contract, particularly if they indicate that the breaching party does not intend to perform properly going forward.
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