Summary
A commercial lease sets the rules for years, and Ontario's Commercial Tenancies Act fills in many of the gaps. Some statutory rules apply only if the lease does not say otherwise; others apply no matter what the lease says. Landlords and tenants who know which is which can negotiate a lease that holds up. This post sets out what the Act says and a general review checklist for both sides.
Who it affects
Landlords and tenants about to sign, renew or amend a commercial lease in Ontario. The Act does not apply to tenancies and tenancy agreements to which the Residential Tenancies Act, 2006 applies (section 2). Section 2.1 also excludes certain property in which the Crown in right of Ontario has an interest.
What the Act says that a lease can change
Re-entry for unpaid rent: section 18(1) deems every lease to allow re-entry if rent is unpaid fifteen days after it was due, "unless it is otherwise agreed". The lease can set a different rule.
Consent to assign or sublet: where a lease made after September 1, 1911 requires consent to assign, sublet or part with possession, section 23(1) deems that consent not to be unreasonably withheld, unless the lease contains an express provision to the contrary.
What the Act says that a lease cannot change
Relief from forfeiture: section 20 lets a tenant apply to court for relief from re-entry or forfeiture, and section 20(6) says it applies "despite any stipulation to the contrary". Some covenants fall outside it, including covenants against assigning or subletting (section 20(7)).
The notice rule for breaches other than rent
Under section 19(2), a landlord's right of re-entry or forfeiture for a breach other than non-payment of rent is not enforceable unless the landlord serves a notice specifying the breach and the tenant fails, within a reasonable time, to remedy it and pay reasonable compensation. Both sides should check how the lease's own default and notice clauses fit with that rule.
What the Act fills in when the lease is silent
Waivers: if a landlord waives a covenant once, section 26 says that waiver does not extend to any other breach, and is not a general waiver, unless an intention to that effect appears.
Local improvement taxes: under section 27(1), unless a lease made after September 1, 1897 specifically provides otherwise, a tenant's covenant to pay taxes does not include taxes assessed for local improvements.
Guarantees and indemnities
Landlords often ask an individual to stand behind a business tenant. The Statute of Frauds, section 4, says no action can be brought on a "special promise to answer for the debt, default or miscarriage of any other person" unless the agreement, or a memorandum or note of it, is in writing and signed by the person to be charged or someone lawfully authorized by them. Whether a particular document is that kind of promise depends on its wording, so have it read before anyone signs.
A general review checklist
These are practical points many parties consider. They are general considerations, not statements of law, and the right answer depends on the deal. 1. Parties and premises: who exactly is the landlord and the tenant, whether there is a guarantor, and how the premises are described. 2. Term and renewal: start date, length, and any renewal or early-termination options and how they are exercised. 3. Rent and other charges: base rent, additional rent, how operating costs and taxes are shared, and when payments are due. 4. Default and remedies: what counts as a default, any notice and cure periods, and whether the lease changes the fifteen-day rule in section 18(1). 5. Use and repairs: permitted use, who repairs what, and who pays for improvements. 6. Insurance: what each side must insure. For breach of a covenant to insure, relief from forfeiture requires the insurance to be in place (section 20(8)). 7. Guarantees: whether anyone is signing personally, for how long and for what amount. 8. Assignment and subletting: whether consent is required and whether the lease expressly displaces the section 23(1) reasonableness proviso. 9. End of the lease: restoration, removal of fixtures and what happens if the tenant stays on.
For tenants and for landlords
Tenants should read twice the clauses on rent and additional rent, term and renewal, repairs, use, assignment, default and notice, and early exit. Landlords should get right the default and cure periods, any guarantee, waiver language and taxes.
What it means
For landlords, clear drafting on default, notice and consent reduces disputes later. For tenants, knowing the protections that cannot be signed away, and the ones that can, shows where to negotiate. For both, the lease and the statute must be read together. Read about common causes of commercial lease disputes.
Key takeaways
The Commercial Tenancies Act does not apply to residential tenancies under the Residential Tenancies Act, 2006 (s. 2).
The fifteen-day re-entry term in s. 18(1) applies unless the lease says otherwise.
The consent proviso in s. 23(1) can be displaced by an express lease term.
Relief from forfeiture under s. 20 applies despite any contrary term, with exceptions.
Review the lease from your own side, landlord or tenant, before you sign.
Related posts: Unpaid commercial rent: Ontario options · Assigning a commercial lease in Ontario
Frequently asked questions
Does the Commercial Tenancies Act apply to every lease?
No. Section 2 says the Act does not apply to tenancies and tenancy agreements to which the Residential Tenancies Act, 2006 applies.
Can a commercial lease change the statutory rules?
Some of them. For example, the fifteen-day re-entry term in section 18(1) applies unless otherwise agreed, and the consent proviso in section 23(1) applies unless the lease contains an express provision to the contrary. Others cannot be contracted out of: section 20 on relief from forfeiture applies despite any stipulation to the contrary.
Should a landlord or a tenant get legal advice before signing?
A lease sets each side's rights for years. Advice before signing lets a landlord or a tenant understand how the lease and the Commercial Tenancies Act work together on their facts.
Whether you're a landlord or a tenant, book a consultation
For help with a lease, see our commercial leasing lawyers in Ottawa.
Francis Mehr LLP handles commercial lease matters for landlords and tenants in Ottawa and across Ontario. Book a consultation: call (613) 226-1011 or contact us.
Written by the lawyers of Francis Mehr LLP. Updated October 30, 2026. This post is general information about Ontario law as of that date, not legal advice. Every lease and every dispute turns on its own wording and facts; get advice on your situation before you act.
