The final paper titled "Data Analysis in Improving Internal Communication of Sales Teams" explores the application of analytical databases to optimize communication processes within sales teams, aiming to increase efficiency, reduce costs, and enhance business results. The subject and objectives of the research, the research question, and the research methods are defined in the introductory section. The evolution of personal selling in the information age is analyzed, emphasizing the adaptation of sales approaches to specific customer needs, and differentiating workgroups from teams, including stages of group development. In the context of business communication, the principles of successful communication are examined, including verbal, non-verbal, and electronic communication, with a special focus on modern digital tools such as WhatsApp and video conferencing platforms. Behavioral psychology is explored through the DISC model, which categorizes personalities into four main types: Red, Yellow, Green, and Blue, providing a deeper understanding of behavioral styles and their impact on team dynamics. The role of the modern manager-leader is considered through leadership skills, leadership styles, and employee development levels, with the aim of building engagement within the sales team. A practical example of the successful implementation of a performance tracking system is presented, demonstrating the advantages and challenges of applying analytical data in daily business operations. The conclusion highlights how effective internal communication and understanding of behavioral psychology significantly improve the working atmosphere and productivity of sales teams. This research offers valuable tools and strategies for managers, leaders, and business communication professionals to successfully lead teams in a dynamic business environment.