The objective of the study is to analyze the professional requirements related to the treatment of assertions regarding the key aspects of the audit in the context of reporting missions. During the audit missions, they must monitor whether the data collection and processing procedures are well established and permanently applied. The idea that it is the duty of the auditor to detect violations of the legislation is unanimously shared. At the same time, the auditor cannot be expected to report issues that do not belong to his competence. Mistakes in financial statements can be committed not only because of non-compliance with the principles of accounting standards, but also for other reasons explained in the article. In order to discover the errors and frauds listed above, the procedures recommended by the International Auditing Standards and those proposed in this paper can be extended. Presentations or disclosures made by an entity's management through financial reports are treated in various ways, which are not limited to the accuracy with which accounting information is processed. Affirming that the information in the financial statements is presented in accordance with the provisions of the accounting and financial reporting framework respectively, it can be concluded that the management, implicitly or explicitly, assumes responsibility for the recognition, evaluation, quantification, presentation and disclosure of the various elements in the statement financial statements and related explanatory notes. In practice, all cases of incorrect financial reporting a serious problem for accountants who want to properly apply accounting provisions, but it is also a challenge for independent auditors. The objective of an audit mission is to provide an assurance that the financial position and financial performance are adequately presented in the financial statements taking into account the provisions of the financial reporting standards. It is important that when starting the audit, the auditor will first of all obtain a sufficient understanding of the terms and conditions of the engagement.