Janis - generally you are correct. However, if a client has a sufficient number of rental properties, I have seen CRA acknowledge that said client is in the business of renting out properties and allow same. This is, however, very rare.
As a general remembrance, rental income is considered PASSIVE income, similar to investment income, and so minimum deductions are allowed against same. However, should a client be providing more services than just a rental property (cleaning of property, etc.,) the nature of the income can change.
Hope this helps.
Jo
