Corporate or in-firm training, as a practice of personnel development, providing relevant knowledge and skills of employees has a long tradition and history of development. Commercial companies that occupy a leading position in their respective markets traditionally invest a significant part of their profits in employee training and development programs, since it is the workforce that is an important factor in the competitiveness and sustainability of companies both in the current and strategic perspective. Professional training and advanced training of employees is an urgent task of personnel development in modern economic conditions, since the speed of technology change, global trends in digitalization, as well as other challenges necessitate a rapid response. Companies that are unable to promptly reproduce the professional competencies of employees are gradually losing their competitive positions in the market. The purpose of this work is to consider the main advantages that thoughtful and systematic work on in-firm employee training provides to companies.