The modern business environment is dynamic and constantly evolving, which affects the change in the structure and behavior of costs in every company. Analysis of the classification of costs according to various criteria, such as time of creation, functions, position in financial statements, bearers, behavior to change the level of activity, significance for making business decisions and the possibility of control, enables a deeper understanding of the impact of costs on organizational processes. Traditional costing methods, such as work order costing and the process costing system, show significant shortcomings and become unreliable methods in providing information on costs and cost price. In order to try to correct this, an activity-based costing method was developed. The ABC method ensures a better insight into the distribution of indirect costs, which are distributed as precisely as possible to the main carriers, and provides a more objective, correct and high-quality valorization of the effects. From this work, it can be concluded that cost accounting remains crucial for making business decisions. Proper cost accounting enables organizations to optimize resources, increase competitiveness and achieve financial success. It is important to choose a costing method that best suits the specifics of an individual organization. Continuous research and application of new cost accounting methods are key to successful cost management in the modern business environment and achieving a sustainable competitive advantage.