Can You Sublease a Commercial Unit in Ontario?
- Aug 4
- 5 min read

If your business has extra space it is not using, or you are trying to get out of a lease early, subleasing can seem like an easy fix. You find someone else to take over the space, they pay rent, and your problem is solved. In practice, though, subleasing a commercial unit in Ontario is usually not that simple. Whether you are allowed to sublease, and what happens if you do, tends to depend on a mix of your lease terms, your landlord, and the person or business you are hoping to bring in as a subtenant. Here is a general look at what tends to matter.
Start With Your Lease, Not Your Plan
Before you go looking for a subtenant, it is worth going back to your original lease and reading the fine print. Most commercial leases in Ontario include a clause dealing with subleasing, assignment, or transfer of the space, and these clauses can vary a lot from one lease to another. Some leases allow subleasing with the landlord's consent, some place conditions on it, and some restrict it fairly heavily. A lease might also draw a distinction between subleasing part of the space and subleasing the whole thing, or between subleasing to a related business versus a completely new tenant.
It is easy to assume that if the lease does not say you cannot sublease, then you are free to do it. That is not always a safe assumption, and it is generally worth having the lease reviewed before you move forward, rather than after you have already found someone interested in the space.
Landlord Consent Usually Matters
Even where a lease allows subleasing, it is common for that right to come with a requirement that the landlord consents first. Landlords often want some say in who occupies their building, since the subtenant's business, reputation, and use of the space can affect the property as a whole. Some leases say the landlord cannot unreasonably withhold consent, while others give the landlord more discretion. What counts as reasonable can depend heavily on the specific wording used and the facts of the situation.
In practice, this usually means giving the landlord notice of the proposed sublease, providing information about the subtenant, and waiting for approval before signing anything or letting the subtenant move in. Skipping this step, even if you believe consent would have been given anyway, may put you in breach of your lease.
Who the Proposed Subtenant Is Can Matter Too
Landlords are not just approving the idea of a sublease, they are often assessing the subtenant itself. Questions that may come up include what kind of business the subtenant runs, whether that use fits within any permitted use clause in the lease, whether the subtenant appears financially stable, and whether their operations might create additional wear, liability, or complaints compared to the original tenant. A landlord may be more comfortable approving a sublease to a business similar to yours than to one in a very different industry, particularly in a retail or mixed use building.
If you are trying to line up a subtenant, it may help to think about how that business would look from the landlord's perspective, not just your own.
You May Still Be on the Hook
One of the most misunderstood parts of subleasing is what happens to the original tenant's responsibilities. In many cases, subleasing does not remove the original tenant from the lease. Unless the lease or a separate agreement says otherwise, the original tenant may remain responsible to the landlord for rent, damage, and other lease obligations, even after a subtenant moves in. If the subtenant stops paying rent or damages the space, the landlord may still look to the original tenant to make things right.
This is different from a full assignment of the lease, where the original tenant may be released from some or all future obligations, depending on how the assignment is structured and what the landlord agrees to. Subleasing and assignment are related but are not the same thing, and it is worth understanding which one you are actually doing before you sign anything with a proposed subtenant.
Putting a Sublease Agreement in Writing
If subleasing looks like it may be possible, it is generally a good idea to put the arrangement in writing, separate from the original lease. A sublease agreement can set out rent, term, what happens if the subtenant defaults, and how responsibilities are divided between the original tenant and the subtenant. Having this in writing may help avoid disputes later, particularly since the original tenant could still be answering to the landlord if something goes wrong.
What This Means for You
Subleasing a commercial unit in Ontario is often possible, but whether it makes sense for your situation depends on your lease terms, your landlord's willingness to consent, who the proposed subtenant is, and how much ongoing liability you are comfortable keeping. Before advertising the space or agreeing to terms with a potential subtenant, it is generally worth having your lease reviewed so you understand what is actually allowed and what steps need to happen first.
Frequently Asked Questions
Q: Can I sublease my commercial space without telling my landlord?
A: This depends on your lease. Many commercial leases require landlord consent before a sublease can go ahead, and moving forward without it may put you in breach, depending on the wording of your specific lease.
Q: If I sublease my unit, am I still responsible for the rent?
A: In many cases, yes, unless your lease or a separate agreement says otherwise. Subleasing does not automatically remove the original tenant's obligations to the landlord, so this is worth confirming before you proceed.
Q: Is subleasing the same as assigning my lease?
A: Not necessarily. They are related concepts but are usually treated differently, particularly when it comes to whether the original tenant remains responsible afterward. It is worth understanding which one applies to your situation.
Q: What if my landlord refuses to consent to a sublease?
A: This can depend on what your lease says about consent and whether it can be reasonably withheld. Whether a refusal is reasonable often depends on the specific facts, and a lawyer can help you understand your options.
Contact DevLaws
If you are considering subleasing your commercial space in Ontario, or you want to understand what your lease actually allows, the team at DevLaws is here to help. Contact DevLaws today to schedule a consultation and talk through your specific situation.
contact@devlaws.com | +1 437 290 0424 | devlaws.com
Disclaimer
This article is provided for general information purposes only and does not constitute legal advice. It is not intended to create a lawyer-client relationship. Laws and regulations can change, and the information here may not reflect the most current developments. Every situation is different, and the information in this article may not apply to your specific circumstances. If you have questions about subleasing a commercial unit, you should consult a qualified lawyer for advice tailored to your situation. DevLaws does not guarantee any particular outcome or result.




