During your review of the revenue accounts at ABC Corporation, a public company, you enquired of management about sales to customer 920424000 BC Ltd., a numbered company The revenue account accumulates sales to a related company. The president of ABC explained that the sales are at very favourable terms to ABC; in fact, the related company pays more than market value for the items it purchases from ABC. Because of ABC's tax credits, the overall tax payable for the 2 companies is smaller if the revenue (and the income) is reported in ABC. This provides the related company with higher expenses, which also lowers its taxable income.

Required: Briefly explain 4 concerns you would have as auditor in this situation.