How the recent changes in the Residential Tenancies Act affect Ontario Landlords? The Residential Tenancies Act regulates how leases are structured to ensure tenants rights are protected under the Act in the event they face unlawful rent increases or eviction, and sets out restrictions on when a Landlord can give notice to the Tenant to vacate. The new Residential Standard Form Lease must be used after April 30th, 2018. The Government has just released a new Residential Standards Form Lease which will become mandatory for tenancy agreements signed after April 30, 2018. If the Landlord fails to use this form, the Tenant can demand the landlord to provide it or withhold up to one month's rent.