In which situation are premiums paid by a business NOT tax deductible as business expenses?

Premiums paid for key person disability income insurance are not tax deductible as business expenses because this type of insurance is designed to provide income to the insured key employee in the event of a disability. The key employee is often a significant contributor to the company's revenue or operations, and any benefits received from such policies are typically considered to be personal in nature rather than a business expense.

In contrast, premiums for health insurance of employees, accident and health plans, and general liability insurance are generally deductible as business expenses because they are necessary for the conduct of business, providing direct benefits to the employees or protecting the company from potential liabilities. This distinction underscores the tax treatment that differentiates personal insurance benefits from those that are strictly business-related.