It is generally assumed that the credibility of a firm's disclosure is enhanced when there is an independent review. This is the basis for the requirement that an independent audit firm attest to the veracity of financial statements. With the passage of Sarbanes-Oxley, publicly-traded North American firms must include a statement about the quality of their internal control system in their financial statements. While the audit of the statements of financial position may be considered to pertain only to that information, the internal control system has a pervasive effect.