The effect of internal control system in accounting audit and field research in İstanbul

This research examines the effect of internal control systems implemented in businesses on the effectiveness of accounting audits. The study was conducted using a mixed research method, combining both quantitative and qualitative data collection techniques. In the quantitative dimension of the research, a survey was administered to 82 participants. Quantitative findings indicate a positive and significant relationship between internal control practices and internal audit effectiveness. Correlation and regression analyses revealed that internal control practices related to cash operations, inventory management, and receivables management positively affect internal audit effectiveness. Additionally, difference tests showed that as professional experience increases, internal control and internal audit scores also increase, and in terms of business structure, joint-stock companies have higher internal control and internal audit values compared to limited liability companies. No significant difference was found in the perception of internal control and internal audit based on job position. In the qualitative dimension of the research, in-depth interviews were conducted with six participants. Qualitative findings demonstrate that internal control practices play a critical role in preventing errors and fraud in businesses, protecting assets, and enhancing the effectiveness of internal audit processes. Interview results revealed that as professional experience increases, the importance given to internal control and internal audit practices also increases, professional titles and management levels shape the perception of internal control, and the legal structure of businesses (joint-stock company, limited liability company, family business) causes differences in internal control approaches. The study offers recommendations that will contribute to businesses improving their internal control systems and audit processes. An effective internal control system enhances the quality of accounting audits, ensures more efficient use of business resources, and strengthens the reliability of financial reports.