The scene is familiar. Your tenant writes: "I have to move in September, but I've found someone to take over the unit." Many landlords answer yes or no on the spot, without realizing they've just stepped into one of the most misunderstood mechanisms in Quebec rental law.
The difference isn't cosmetic. Depending on whether it's a sublease or a lease assignment, the person responsible for the rent changes, your right to refuse changes, and the future of the lease itself changes. This guide walks through the mechanics from the landlord's side.
Two mechanisms, two opposite consequences
Quebec's Civil Code (art. 1870 and following) lets a tenant sublet the unit or assign the lease, provided they notify the landlord. On the ground the two look alike — someone else moves in — but everything else differs.
| Question | Sublease | Lease assignment |
|---|---|---|
| Who stays liable for the rent? | The original tenant, always | The assignee alone — the original tenant exits the lease |
| Who do you pursue for non-payment? | The main tenant | The new tenant (assignee) |
| Duration | A period shorter than the lease — the original tenant can return | The rest of the lease, permanently |
| Your lease terms | Unchanged | Passed on as-is to the assignee |
| Grounds to refuse | Serious grounds only | Any serious ground — and the refusal ends the lease (Law 31) |
The 15-day clock: the rule that traps landlords
When the tenant sends you a notice of sublease or assignment, they must give you the name and address of the proposed person. From the moment you receive that notice, you have 15 days to respond.
- The tenant must notify you in writing, naming the proposed candidate.
- You have 15 days from receipt to refuse, stating your grounds.
- Past that deadline with no reply from you, consent is presumed.
- A refusal must state a serious ground — not a bare "no."
In practice: the moment a notice arrives, request the candidate's full file (income, employment, references, rental history). You can't extend the deadline while you wait for documents, so start verification immediately. Our guide to what you can legally verify about an applicant sets out what you're entitled to ask for.
What you can refuse — and what you can't
A refusal must rest on a serious ground. A serious ground is an objective one, tied to the candidate's ability to meet the lease obligations — never a ground tied to the person themselves.
- Valid ground: demonstrated inability to pay (insufficient income, history of non-payment).
- Valid ground: an incomplete file, or the candidate refusing to provide the usual information.
- Valid ground: documented history of disturbing other occupants or damaging property.
- Invalid ground: origin, religion, language, age, disability, sexual orientation, civil status, pregnancy, social condition — the Charter applies in full.
- Invalid ground: simply wanting the unit back to re-rent it for more.
What Law 31 changed for assignments
Since February 2024, Law 31 has flipped the balance of power on lease assignments. A landlord may now refuse an assignment on any serious ground — but that refusal ends the lease on the date the tenant proposed for the assignment.
That's a real trade-off, not a formality. Refusing means getting the unit back and being able to re-list it at market rent; it also means absorbing the vacancy and the search for a new tenant. Accepting means avoiding vacancy but inheriting an occupant you didn't choose, on the same lease terms.
For the full assignment procedure and its deadlines, see our dedicated guide: lease assignment since Law 31.
Refuse or accept: how to decide
The right instinct is neither "I refuse on principle" nor "I accept to avoid trouble." It's to compare two scenarios with actual numbers.
| Scenario | What you gain | What you risk |
|---|---|---|
| Accept the assignment | No vacancy, immediate transition, no marketing costs | A tenant you didn't select, at the current rent |
| Refuse the assignment | The lease ends; you choose the next tenant and reposition the rent | One or more months of vacancy, plus the cost of re-listing |
The math turns on two numbers above all: the gap between your current rent and market rent, and the real cost of a month of vacancy. To put a figure on the second, use our vacancy cost calculator.
If you accept: screen the candidate like any other
The most common mistake is treating the candidate proposed by the outgoing tenant as a file that's already been vetted. It hasn't. The original tenant wants out quickly; once the assignment goes through, they carry none of the non-payment risk.
- Require the same file as for any walk-in applicant: proof of income, employment, references from the last landlord.
- Get the candidate's written consent before any credit or rental-history check.
- Apply exactly the same objective criteria as to any other applicant — same thresholds, same questions.
- Document your decision and your grounds, within the 15 days.
Common mistakes to avoid
- Letting the 15 days lapse: silence equals consent, even if the file is weak.
- Refusing without written, objective grounds: a poorly justified refusal gets overturned at the TAL.
- Confusing sublease and assignment: accepting an open-ended "sublease" is an assignment in disguise.
- Accepting the candidate without screening, because the outgoing tenant "vouches" for them.
- Using the assignment to raise the rent: the lease terms pass to the assignee unchanged.
In short
- Sublease: your tenant stays liable. Assignment: they exit the lease and the assignee takes their place.
- You have 15 days to refuse on serious grounds — past that, you've consented.
- Since Law 31, refusing an assignment ends the lease: it's a trade-off between vacancy and repositioning the rent.
- Grounds for refusal must be objective: the Charter bars any refusal based on who the person is.
- If you accept, screen the candidate as rigorously as any other.