It's more common than you might think: a tenant reaches out to say they want to move out early and asks if someone else can take over the unit. Sometimes they say "sublet," sometimes "transfer the lease." The distinction matters — legally and practically — and your rights in each case are different.
Subletting vs. Assignment: What's the Difference?
These two terms are often used interchangeably, but under the Residential Tenancies Act they mean different things.
A sublet is when the original tenant temporarily moves out, lets someone else live in the unit, and then plans to return before the lease ends. The original tenant remains on the lease and is still legally responsible for rent and the condition of the unit. The person staying there (the subtenant) has an arrangement with the original tenant, not with you.
An assignment is when the original tenant wants to permanently transfer the lease to a new person. After a valid assignment, the assignee becomes your tenant and the original tenant is no longer party to the tenancy.
Knowing which one is being requested changes how you handle it.
The Landlord's Rights: Consent Required, But Not Unreasonably Withheld
For both subletting and assignment, the tenant must get your consent before proceeding. They should make the request in writing, and you have 7 days to respond.
If you don't respond within 7 days, you're deemed to have given consent — so don't sit on the request.
Here's the critical part: you cannot unreasonably withhold consent. The RTA sets the standard. You can refuse a specific subtenant or assignee for legitimate reasons — poor credit history, a pattern of non-payment, or failing to meet reasonable income criteria. But you cannot refuse simply because you'd rather have the unit back or want to select someone yourself from scratch.
If you refuse without good reason, the tenant can apply to the LTB, and the board can authorize the sublet or assignment without your consent.
When You Can Refuse Outright
There is one situation where you can decline entirely: for an assignment request, you can refuse and instead offer to let the tenant out of the lease — effectively agreeing to end the tenancy.
If you refuse the assignment (for any reason), the tenant then has the right to give you 30 days' notice and terminate the tenancy. This can actually work for both parties — the tenant gets out cleanly, and you get a fresh start with a new tenant of your choosing.
This option only applies to assignments, not sublets.
Practical Steps When You Receive a Request
1. Get it in writing. Ask for a written request that includes the proposed subtenant or assignee's name, and request the same information you'd collect from any applicant — ID, proof of income, references.
2. Screen them properly. Run the same process you'd use for any new tenant: credit check, employment verification, references. If the proposed occupant doesn't meet your usual criteria, document your reasons clearly.
3. Respond within 7 days. Approve or decline, put it in writing, and keep a copy.
4. Put the arrangement in writing. For a sublet, make sure the original tenant understands they remain legally responsible. A written agreement between you, the original tenant, and the subtenant that outlines responsibilities prevents confusion.
What If a Tenant Sublets Without Permission?
If a tenant sublets without getting your consent first, you can serve an N5 Notice to End a Tenancy for unauthorized subletting. The tenant then has an opportunity to remedy the situation — typically by ending the unauthorized sublet.
Acting promptly matters here. Letting an unauthorized sublet continue without responding can complicate your legal position if the matter later goes to the LTB.
Practical Notes for London, St. Thomas, and Sarnia Landlords
Sublet and assignment requests tend to come up most with students (relocating between academic years), tenants who've had a job change, or people who've found a better living situation. In London especially, with a significant student population near Western University and Fanshawe College, this is a scenario that comes up regularly.
Understanding the process in advance — rather than scrambling when a request arrives — keeps you from making a decision under pressure. This is also an area where property managers like Prospera Properties can help: screening proposed occupants, responding within the legal timeframe, and making sure any resulting agreement is documented properly.
Key Takeaways
- Subletting = temporary; original tenant stays legally responsible. Assignment = permanent transfer of the tenancy.
- Tenants need your written consent before doing either.
- You have 7 days to respond — silence is deemed consent.
- You can't unreasonably withhold consent, but you can screen the proposed occupant using your normal criteria.
- For assignments: if you refuse, the tenant can give 30 days' notice and exit the tenancy.
- Unauthorized subletting can be addressed with an N5 notice.