In plain English
A landlord must give at least 90 days' written notice before increasing the rent (Form N1), and generally only once every 12 months.
The statute text
116 (1) A landlord shall not increase the rent charged to a tenant for a rental unit without first giving the tenant at least 90 days written notice of the landlord’s intention to do so.
(2) Subsection (1) applies even if the rent charged is increased in accordance with an order under section 126.
(3) The notice shall be in a form approved by the Board and shall set out the landlord’s intention to increase the rent and the amount of the new rent.
(4) An increase in rent is void if the landlord has not given the notice required by this section, and the landlord must give a new notice before the landlord can take the increase.
View this section on the official Ontario e-Laws site →
Reproduced under the King’s Printer for Ontario / Open Government Licence – Ontario. Confirm against the official e-Laws consolidation before relying on it.