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CIVIL DISPUTES GUIDE
Commercial Landlord & Tenant Disputes in Ontario
A practical guide to commercial lease disputes, rent arrears, default, lockouts, distress, repairs, use clauses, assignments, renewals, deposits, guarantees and civil court remedies.
Commercial tenancy disputes can move quickly. A missed rent payment, disputed repair, failed renewal or improper lockout can affect operations, cash flow and the value of the business. The lease wording and the commercial context matter from the first step.
Prepared by Tatyana Trusz, Trusz Law • Updated July 2026 • 15 min read
QUICK ANSWER
How are commercial lease disputes different?
Commercial landlord and tenant disputes are usually governed by the lease, Ontario’s Commercial Tenancies Act and civil court remedies—not the residential Landlord and Tenant Board process.
The first question is usually not who is upset. It is what the lease says, what notice was required, what default occurred, what remedies are available and whether urgent business harm needs to be prevented.
IN THIS GUIDE
RELATED CIVIL DISPUTES
LEASE DISPUTE?
The lease, notices and timing often decide the next move.
Commercial tenancy issues can escalate quickly when operations are at stake.
THE SHORT ANSWER
Start with the lease, the default and the remedy being used
A commercial lease dispute should usually be assessed through five questions:
- What does the lease say?
- What default, breach or disagreement occurred?
- Was the required notice given?
- What remedy is being used or threatened?
- What business harm will occur if the issue is not resolved quickly?
The same facts can look very different depending on whether the dispute is about rent, possession, repairs, termination, renewal, assignment, exclusive use, quiet enjoyment or personal guarantees.
KEY TAKEAWAYS
At a glance
- Ontario’s Commercial Tenancies Act governs many commercial landlord and tenant issues, but the lease may take precedence in important ways.
- The Residential Tenancies Act and Landlord and Tenant Board process generally do not apply to commercial leases.
- Common disputes include rent arrears, default notices, lockouts, distress, repairs, renewal rights, assignment and use clauses.
- Landlords and tenants should be careful before terminating, changing locks, seizing goods or stopping rent.
- Urgent court relief may be needed where possession, business operations or property are at immediate risk.
- Ontario Small Claims Court currently handles monetary claims up to $50,000.
- Ontario’s basic limitation period is generally two years from discovery of the claim.
COMMON DISPUTES
What issues commonly arise in commercial leases?
| Issue | Common dispute |
|---|---|
| Rent arrears | Base rent, additional rent, HST, CAM, taxes, utilities, interest and deposits. |
| Default notices | Whether notice was required, valid, properly served and capable of being cured. |
| Lockout or termination | Whether possession was lawfully ended and what damages follow. |
| Distress or seizure | Whether goods can be seized for rent arrears and whether the process was proper. |
| Repairs and maintenance | Roof, HVAC, plumbing, access, fixtures, common areas and operating costs. |
| Use and exclusivity | Permitted use, prohibited use, exclusivity, zoning, licensing and compliance. |
| Assignment or sublease | Consent, conditions, continuing liability and sale-of-business issues. |
| Renewal options | Notice deadlines, rent-setting, conditions and whether the option was exercised properly. |
RENT ARREARS & DEFAULT
What happens when rent or additional rent is unpaid?
Rent disputes may involve more than monthly base rent.
Commercial leases often define rent to include:
- base rent;
- additional rent;
- common-area maintenance charges;
- property taxes;
- utilities;
- insurance contributions;
- HST;
- interest;
- administration fees; and
- recovery of landlord costs.
Before taking action, both sides should review the lease, rent ledger, notices, payment history and any rent deferral, abatement or side agreement.
Tenants should be careful about withholding rent without legal advice. Landlords should be careful about default remedies, notice requirements and whether the lease has been terminated or affirmed through later conduct.
LOCKOUT, TERMINATION & DISTRESS
What are the risks with lockouts and seizure of goods?
Commercial landlords may have remedies that do not exist in the same way in residential tenancies, but those remedies carry legal risk if used incorrectly.
Issues can include:
- whether the lease permits termination or re-entry;
- whether statutory or contractual notice was required;
- whether arrears were properly calculated;
- whether the landlord elected a remedy inconsistently;
- whether goods can be seized for distress;
- whether third-party or exempt property is involved;
- whether the process escalates damages; and
- whether urgent injunctive relief is needed.
A landlord changing locks or seizing goods, and a tenant responding to those steps, should both obtain advice quickly because possession and business continuity may be at stake.
“In a commercial lease dispute, speed matters—but speed without the lease, notices and remedy analysis can create the next lawsuit.”
— Trusz Law
REPAIRS, MAINTENANCE & USE
How do repair and operating disputes arise?
Commercial lease repair disputes often depend on detailed lease wording.
Common issues include:
- who maintains HVAC, roof, plumbing, electrical and structural elements;
- whether the issue is capital repair, ordinary maintenance or tenant damage;
- access for repairs;
- interruption of business operations;
- abatement, set-off or rent relief;
- common-area maintenance charges;
- landlord work vs. tenant work;
- permits, licensing and code compliance; and
- whether the premises can still be used for the permitted purpose.
Use-clause disputes can be equally important. A tenant may need a specific permitted use for licensing, signage, exclusivity or zoning. A landlord may seek to restrict use, competitors, nuisance, alterations or illegal activity.
ASSIGNMENT, SUBLEASE & RENEWAL
What happens when the tenant wants to sell, assign, sublet or renew?
Assignment and sublease issues often arise when a tenant sells a business, downsizes, relocates or brings in a new operator.
Review:
- whether landlord consent is required;
- what information the landlord can request;
- whether consent can be withheld;
- whether conditions or fees apply;
- whether the original tenant remains liable;
- whether guarantors remain liable;
- whether use restrictions affect the new operator; and
- whether arrears or defaults must be cured first.
Renewal options require special attention. Missing a notice deadline or failing to satisfy conditions can cause a tenant to lose a valuable right to remain in the premises.
EVIDENCE
What evidence matters in a commercial lease dispute?
Useful evidence may include:
- the lease and all amendments;
- offers to lease and side letters;
- rent ledgers and payment history;
- default notices and service records;
- correspondence about arrears, repairs or access;
- photos and videos of premises conditions;
- inspection reports and contractor estimates;
- maintenance and repair records;
- insurance documents;
- assignment, sublease or sale documents;
- guarantees and indemnities;
- business-interruption evidence; and
- documents showing mitigation and loss.
Both landlords and tenants should preserve evidence early, especially where possession, goods, repairs or urgent relief are involved.
COURT OPTIONS
Where are commercial lease disputes resolved?
Commercial lease disputes are usually civil matters rather than residential Landlord and Tenant Board matters.
Small Claims Court
Ontario Small Claims Court currently handles claims for money or return of personal property up to $50,000, not including interest and costs. This may be relevant for rent arrears, deposits, smaller damages claims or return of property.
Superior Court of Justice
Superior Court may be needed for injunctions, possession-related urgent relief, larger claims, declarations, complex lease disputes or remedies beyond the Small Claims Court limit.
Negotiation, mediation or settlement
Many commercial lease disputes settle through payment plans, termination agreements, rent abatements, repairs, releases or negotiated move-out terms.
Limitation periods
Ontario’s basic limitation period is generally two years from discovery of the claim. Deadlines should be checked quickly.
COMMON MISTAKES
Problems that make commercial lease disputes more expensive
Assuming residential tenancy rules apply.
Commercial leases follow a different framework.
Not reading the lease before acting.
Default remedies, notice, cure periods and costs are often lease-specific.
Changing locks without proper analysis.
A wrongful lockout can create significant exposure.
Seizing goods without proper process.
Distress is technical and risky if used improperly.
Withholding rent without advice.
Tenants may trigger default remedies even where they have complaints.
Missing renewal-option deadlines.
A valuable lease right can be lost by late notice.
Ignoring personal guarantees.
Guarantors may remain exposed even after business changes.
Failing to document repair issues.
Photos, notices, estimates and inspection records matter.
Waiting too long to act.
Delay can affect evidence, remedies, business operations and limitation periods.
HOW TRUSZ LAW CAN HELP
Assess the lease, the remedy and the business consequences before the dispute escalates.
Trusz Law assists with Ontario commercial landlord and tenant disputes, including rent arrears, default notices, lockouts, distress, repairs, use clauses, assignment and sublease issues, renewal disputes, lease termination, guarantees and settlement negotiations.
Depending on the matter, that may include reviewing the lease, notices, rent ledger, evidence, available remedies, urgent relief options, Small Claims Court or Superior Court strategy and negotiated resolution terms.
The goal is practical: protect the business position, avoid unnecessary escalation and choose a path that fits the value and urgency of the dispute.
FREQUENTLY ASKED QUESTIONS
Commercial landlord and tenant questions people often ask
Do commercial lease disputes go to the Landlord and Tenant Board?
Generally no. The Landlord and Tenant Board deals with residential tenancies. Commercial tenancy disputes are usually governed by the lease, the Commercial Tenancies Act and civil court remedies.
What law governs commercial landlord and tenant disputes in Ontario?
Ontario’s Commercial Tenancies Act outlines many rights and obligations, but the signed commercial lease may take precedence in important ways.
Can a commercial landlord lock out a tenant?
Commercial lockouts can be legally complex and lease-specific. Landlords should get advice before changing locks, and tenants should get advice quickly if locked out.
Can a commercial landlord seize tenant goods for unpaid rent?
Commercial distress may be available in some circumstances, but it is technical and risky if done incorrectly.
Can a commercial tenant withhold rent because repairs are needed?
Withholding rent can be risky and may trigger default remedies. The lease, facts and available remedies should be reviewed first.
What is additional rent?
Additional rent may include costs such as property taxes, CAM, utilities, insurance, HST, interest and landlord recovery costs, depending on the lease.
What happens if a tenant misses a renewal deadline?
The tenant may lose the renewal right if the lease requires strict notice by a certain date, though the facts and wording should be reviewed.
Can a tenant assign or sublease commercial premises?
It depends on the lease. Landlord consent, conditions, fees, continuing liability and default status may all matter.
Can a guarantor be sued for commercial lease arrears?
Often yes, depending on the wording of the guarantee, lease changes, assignment history and arrears claimed.
Can commercial lease disputes go to Small Claims Court?
Yes, monetary claims up to $50,000 may be brought in Ontario Small Claims Court, not including interest and costs.
When is Superior Court needed?
Superior Court may be needed for injunctions, urgent possession issues, larger claims, declarations or complex lease disputes.
When should I speak with a lawyer?
Legal advice is important before lockouts, distress, lease termination, withholding rent, missing renewal deadlines, assignment disputes or urgent court relief.
OFFICIAL RESOURCES
Further reading
ABOUT THIS RESOURCE
Prepared by Tatyana Trusz, Trusz Law. This resource is for general information only and is not legal advice. Commercial lease disputes depend on the lease, notices, conduct, remedies, evidence, urgency and current law. Last reviewed July 2026.
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