Disputes between landlords and tenants in Ontario are decided by the Landlord and Tenant Board under the Residential Tenancies Act, 2006. The Board is an evidence-based tribunal: it decides matters on a balance of probabilities, based on what the parties can actually prove. Many otherwise valid cases fail not because the underlying facts are wrong, but because the evidence is thin, informal, or gathered in a way that does not stand up. This page explains what kind of evidence holds up at the LTB, and where a lawful investigation fits. It is general information, not legal advice.
The Board decides on proof, not assertion
Whatever the issue, an unauthorized sublet, a unit that is not actually being occupied as claimed, a misrepresentation about who lives where, or a suspicion that a notice was served in bad faith, the Board does not act on belief. It acts on evidence. The party who has to prove something must bring documentation that is specific, dated, and credible. Vague recollection and second-hand accounts carry little weight against a well-documented record.
That is the gap a lawful investigation can close. The role is not to manufacture a case. It is to document, properly, what is actually happening, so that a genuine issue can be proven rather than merely alleged.
What holds up
Evidence tends to hold up at the LTB when it is contemporaneous, specific, and lawfully obtained. Timestamped observation of who is occupying a unit, over a period rather than on a single day, is far more persuasive than an isolated photograph. A documented pattern, dates, times, what was observed, and from where, lets an adjudicator see the whole picture rather than a fragment. Records that are lawfully available, such as public listings advertising a unit for sublet, can corroborate what observation suggests.
The documentation standard is the same one that applies to any serious evidence: a clear record of what was observed, when, and by whom, gathered from lawful vantage points, and presented completely rather than selectively. That is what allows the evidence to withstand challenge from the other side.
What does not hold up
Evidence is discounted, or excluded outright, when it is gathered unlawfully. Entering a unit or private property without authority, intruding where a tenant has a reasonable expectation of privacy, or intercepting private communications does not strengthen a case. It weakens it, and it can expose the landlord to liability. A single ambiguous image, an anonymous tip with nothing behind it, or a timeline the landlord cannot substantiate will not carry a hearing.
The bad-faith dimension
The evidentiary standard cuts in both directions, and landlords should understand this. Where a landlord ends a tenancy for their own use, the Act requires good faith, and the Board can consider the landlord’s conduct before and after the tenant leaves, whether similar notices were served before, and what actually happened to the unit afterward. Bad-faith findings carry substantial remedies for former tenants. We deal with that dimension in Bad-faith evictions and the LTB. The lesson for a landlord acting in good faith is the same as for a tenant: the record you can prove is the case you have.
The practical takeaway
If you are heading toward the LTB, the strength of your position is the strength of your evidence. Before a hearing, the useful question is not “do I believe this is happening” but “can I prove it, in a way that holds up.” A lawful, well-documented investigation is one way to close that gap where a genuine issue exists.
Not legal advice
This page is general information about Ontario law and is not legal advice. LTB matters turn on their specific facts and on the Residential Tenancies Act; consult a lawyer or licensed paralegal for a specific case.