Mandatory audit is conducted in the following cases: the organization has organizational and legal form of an open joint stock company, the organization is a credit institution, credit bureaus, insurance companies, mutual insurance companies, commodity or stock exchange, investment fund, state budget funds, fund, source of education funds which are voluntary contributions of individuals and legal entities, the total revenue from product sales (performance works, services) organizations (except for agricultural cooperatives and unions of cooperatives) for the preceding fiscal year exceeds 50 million rubles, or the amount of assets on the balance sheet At the end of the year preceding the accounting year, more than 20 million rubles. For municipal enterprises Law of the Russian Federation financial performance may be reduced, in other cases established by federal laws. Mandatory audit is conducted annually. Mandatory audit of accounting (financial) statements of organizations whose securities are admitted to trading on stock exchanges and (or) other trade in the securities market and other credit institutions and insurance companies, private pension funds, as well as the consolidated financial statements will only audit organizations. The contract for carrying out statutory audits of accounting (financial) statements of the organization, the authorized (share) capital of which state ownership is not less than 25 percent, as well as to conduct accounting (financial) statements of state unitary enterprises or municipal unitary enterprise is up to place an order through an auction in the form of open competition in procedure stipulated by the Federal Law of 21 July 2005 N 94-FZ "On placing orders for goods, works and services for state and municipal needs." Tax Audit Tax Audit as separate type of audit in the law is selected and assigned to the audit-related services and, therefore, is not mandatory. It may be part of a mandatory or proactive audit and may act as a separately provided to audit-related services. In the case of validation of calculation and payment of taxes shall be done from a position of influence tax articles reporting on the reliability of financial (Accounting) in general, and because a number of factors affecting the accuracy of tax reporting it can not be accounted for, since it does not significantly affect the reliability of financial (accounting) reporting. In an audit of accounting (financial) statements, the auditor selected a way to verify the correctness of the calculation and payment of taxes and other obligatory payments. However, an audit can not cover the entire amount of information that affects the tax liabilities of the organization, and can not serve as the sole basis for expressing an opinion on tax reporting. Therefore, many organizations for which general audit is required when entering into contracts with audit firms particularly emphasize the auditors for tax audits and separately indicate the amount of work on tax audit.