You can only serve a notice to the tenants once an Agreement of Purchase and Sale has been signed and the purchaser requires possession of the unit to move in. At that point you would issue the tenants a notice of termination on behalf of the purchaser. The form required for this reason is a Form N12 with 60 days’ notice and you can obtain it from the Landlord and Tenant Board’s website at https://tribunalsontario.ca/ltb/forms/#landlord-forms. Please note that if the property has more than three units, the termination procedures are different than above.
As of July 21, 2020 the landlord is required to give the tenant one month’s rent as compensation, or offer the tenant another acceptable unit if pursuing the N12 notice on behalf of the purchaser. The compensation must be given before the termination date on the notice.