The information systems in the accounting and audit, their functions, examples of using information systems for budget institutions at different levels are considered in this work. The main precondition for the audit is the mutual interest of the enterprise in the person of its owners, the state, in the person of the respective fiscal authorities, which make taxes and fees and personally the auditor in ensuring the reality and reliability of accounting and reporting. An audit is a mandatory part of the civilized functioning of the market economy of each country. According to historical generalizations, the prerequisites for the audit may be called the following: – firstly, to resolve misunderstandings between the tax authorities and the governing bodies representing the interests of the owners in raising the efficiency of production, state control was already insufficient, since it protected only the interests of the state; – secondly, auditors have become indispensable and disinterested parties – court and arbitration, which upheld justice; – thirdly, the development of audit was also facilitated by the delineation of functions and the interest of entrepreneurs in the correct and impartial reflection of business operations, therefore, the owners of companies began to hire a special independent control unit. Thus, the main essence of the audit is the provision of practical assistance to the management and economic services of the enterprise in the management and display of business processes, the management of its finances, as well as the proper conduct of financial and managerial accounting in order to make effective management decisions, provide various consultations, etc. Auditors use information systems to better and quickly obtain the result. Information systems are a set of information, hardware–software and technological tools, telecommunication facilities, databases and data banks, methods and procedures, management personnel that implement the functions of collecting, processing, storing and processing information for the preparation and adoption of effective management decisions. Modern information systems can not only fully satisfy the requirements of production systems, but also act as an important prerequisite for their development. Modern management information systems improve communication between management members, remote structural units, carry out an analysis of economic activity not only retrospective but also promising, carry out monitoring online.