Modern postal law is faced with many changes and challenges. It is crucial to show the development of the postal market in the Republic of Croatia with all the changes brought about by the entry into the European Union, which is characterized by a change in the way the postal market functions. The development of postal law leads to international cooperation and improvement of branches of the postal service. After the exclusive jurisdiction of the state for postal services, monopolies and postal coercion, the postal services market is liberalized. Since joining the European Union in 2013, our legislation has been harmonized with the postal directives, and work is being done to create an internal market of the European Union that functions in a unique way. Through the definition and division of postal services into universal, substitute and other, the role of the Croatian Regulatory Agency for Network Activities as a body authorized to enact implementing regulations and determine the provider of these services is shown. The strategies adopted by the competent ministry create a framework and work plan for the period ahead. With the emergence of the coronavirus pandemic in the last three years and the progress of information and communication technologies, there are new trends that postal law has to face. By researching the user experience in the field of postal law services, we come to know in which direction to go regarding further investments in infrastructure. Through market research, we can adapt to changes in a timely manner so that we protect the employees of postal service providers and direct changes to improving the quality of existing services and introducing new ones that the market is looking for. By introducing new services that can compete on the world market, we can resist the decline of traditional postal services by diversifying operations and adapting to the growth of electronic services.