What threat may arise when fees from an assurance client represent a large part of an individual's revenue?

When fees from an assurance client constitute a significant portion of an individual's revenue, this situation creates a self-interest threat. The primary concern here is that the auditor may become overly reliant on that client for income, which can compromise their objectivity and impartiality.

When a substantial portion of an auditor's revenue is tied to a single client, there may be a subconscious bias towards that client to maintain the relationship and, by extension, the income. This financial dependency can lead the auditor to make decisions that favor the client's interests rather than ensuring an unbiased and fair assessment of their financial statements. Consequently, the integrity of the audit could be compromised, as the auditor may feel pressured, whether consciously or subconsciously, to overlook issues or avoid criticizing the client’s financial reporting.

This emphasizes the importance of maintaining independence and objectivity in auditing to uphold the credibility of the assurance services provided to clients.