In Ontario, you could be responsible for a former roommate's rent years after you’ve left a leased property, due to a glaring blindspot in the Residential Tenancies Act (RTA) that successive provincial governments simply haven’t fixed.

The problem arises when there's a "joint tenancy" in which two or more tenants signed one lease, and someone wants to leave while other tenants want to stay.

The departing tenant tells the landlord that they’re leaving and will no longer be responsible for rent. In doing so, the departing tenant is effectively asking for a lease amendment (even if the tenancy is month-to-month following a lease’s term expiration).

But what happens if the landlord refuses the request? Well, things get complicated.

The RTA doesn't clarify parties' rights, even though renters encounter these situations quite often.

As a result, Landlord and Tenant Board (LTB) adjudicators consistently struggle to resolve these conflicts reasonably. In doing so, they typically start by first determining whether there’s a "joint tenancy" or “tenancy in common”.

The distinction between these two terms seems to confuse everyone. But the main thing to understand is that with a tenancy in common, renters are regarded as having separate leases with the landlord. They can terminate these easily and remaining tenants won’t be much affected.

In a joint tenancy, by contrast, multiple tenants sign one lease together and, per section 17 of Ontario’s mandatory standard residential lease, "[u]nless otherwise agreed…each tenant is responsible for all tenant obligations…including the full amount of rent."

The only scenario in which the RTA clearly contemplates one party unilaterally terminating their “interest” in a joint tenancy is where the tenant or their child has "experienced violence or another form of abuse."

Otherwise, absent a landlord’s agreement to let a departing tenant loose, the only other option tenants have is to say they're assigning their lease interest to a remaining roommate or a new one. And in this scenario, they may argue the landlord cannot "arbitrarily or unreasonably" refuse assignment per section 14 of the standard lease.

But that's an imperfect solution. Namely because section 14 (and the RTA section it’s based on) refers to assignment of a rental “unit” rather than a rental "interest". And to my knowledge, the LTB has never endorsed the move.

Furthermore, a landlord's assignment refusal may be regarded as not "unreasonable" if they can argue the departing tenant's credentials (e.g., income, credit score, etc.) were the primary reason they agreed to the lease in the first place.

At that point a departing tenant is out of options. Which is absurd.

But the solution is simple: add a provision to the RTA stating that if tenants are not in arrears, a landlord may not refuse a departing tenant's request to relinquish their interest in a month-to-month lease.

Marc Z. Goldgrub is a lawyer at Green Economy Law Professional Corporation, a boutique Toronto law firm with a focus on green business, psychedelics, and housing.