What do we call income that is not derived from core business operations?

Non-Operating Income refers to the revenue generated from activities that are not part of a company’s main business operations. This type of income can include things like interest earned on investments, gains from the sale of assets, or revenue from ancillary services. Non-Operating Income is important for financial analysis as it can provide a more complete picture of a company's overall profitability, beyond just what is generated from its primary business activities. Understanding this distinction helps stakeholders assess the sustainability and health of a business, as well as its ability to generate revenue from its core operations versus auxiliary sources.

In contrast, Primary Income and Operating Income focus strictly on revenue generated through the primary activities of a business, while Sustainable Income relates to the capacity of a business to maintain its income levels over time, often blurring the lines with operating performance. Hence, Non-Operating Income is the appropriate term for income not tied to core business functions.