Check the RTB’s current rent-increase rules and calculator first, as the permitted limit can depend on the date and details of the tenancy. Keep the rent review notice, tenancy agreement, payment records and any messages with your landlord. You can contact the RTB to ask whether the issue should be raised as a tenancy dispute or reported through its enforcement process, and submit the relevant evidence through the RTB’s official channels. The outcome is decided by the RTB based on the facts of the case; a solicitor can advise on a complicated dispute.