Internal audit is an activity that provides independent and objective assurance and consulting services that contribute to the improvement of an organization's economic performance. This research article explores the essence of external and internal audit, as well as the methodology for implementing internal control in organizations. The organization of an effective internal control system was also examined and its capabilities identified. Furthermore, the characteristics of external and internal audit were characterized. Based on the identification of the main advantages and disadvantages of internal audit, recommendations for improving the company's operations were made. Thus, internal audit can become an important tool for financial control. Internal financial control has been established as a key process for improving an organization's performance and ensuring compliance with rules and policies.