What is the initial step in determining whether a company qualifies as very large for corporation tax?

The determination of whether a company qualifies as very large for corporation tax primarily hinges on the calculation of augmented profits. This metric is pivotal because it accounts for various forms of income and expenditures, providing a comprehensive view of the company's financial standing. By focusing on augmented profits, tax authorities can accurately assess the company's capacity to contribute to taxation, reflecting its overall economic footprint within the market.

While the other options—total assets, market share, and the number of employees—can provide insights into a company's scale and operations, they do not specifically address the financial performance and profitability that are critical to the tax qualification process. Augmented profits serve as a definitive criterion, ensuring that size categorizations are rooted in tangible financial outcomes rather than mere structural attributes. Thus, understanding this focus on augmented profits helps clarify the tax implications for very large corporations.