In today’s world, dominated by the rapidly growing e-commerce industry, customer service is an integral part of any business strategy. A significant task of customer service is to integrate all areas of a company’s operations in order to meet customer needs. Through customer service, a company has the opportunity to learn about customer expectations and, thanks to efficient customer service, the company should be able to meet their needs. With this in mind, it should be noted that the aim of the research was to identify the role of customer service in selected courier companies. As a result of this objective, the research problem was formulated in the form of the following question: What is the importance of customer service in the activities of selected courier companies? The article uses theoretical research methods such as analysis, synthesis, inference, and comparison, as well as a practical research method, namely a diagnostic survey using a questionnaire addressed to users of courier services. The presented research was limited by the subjective scope of studies, which covers the activities of selected courier companies: InPost, DHL, and DPD. The subject scope defines the importance of customer service in the operations of the discussed courier companies. The time scope covers the years 2010–2025, while the spatial scope covers the territory of Poland.