Reserve claimed against business income is business income when reversed
4. ... If the original gain on the sale of real property was categorized in a previous year as income from an active business, amounts included in income in subsequent years in respect of the realization of the mortgage reserve pursuant to subparagraph 12(1)(e)(ii), are considered to be income from an active business. This also applies to any mortgage interest received pertaining to such mortgage.
Meaning of "pertains to" or "incident to"
5. … The courts have found that, in interpreting the meaning of "pertains to" or "incident to" in context, there has to be a financial relationship of dependence of some substance between the property in question and the active business before the property is considered to be incident to or to pertain to the active business carried on by the corporation. In addition, the operations of the business have to have some reliance on the property such that the property is a back-up asset that could support the business operations either on a regular basis or from time to time.
Whether corporation’s profit is from property
8. If a corporation is incorporated to earn income by doing business, there is a general presumption that profits arising from its activities are derived from a business … . However, in some circumstances, a corporation's entire profits can be characterized as income from property, as might be the case where the corporation is formed for the sole purpose of holding shares of a second corporation or holding a property to be rented with limited landlord responsibilities. It is, of course, quite possible that a corporation will earn income from property as well as income from a business carried on, if such property income is not income from another separate business.