The world and the countries, in general, are moving to change the form of government and public sector management from the traditional form that relies on providing services in-person to use the technology and employ it to provide various government services and communicate with citizens and companies completely electronically. Most of the countries in the world began to implement e-government and move from the traditional form of service provision to the electronic form since the beginning of the 21st century. With the entry of the current year, the importance of e-government has increased dramatically due to the spread of the Coronavirus pandemic in the world and the urgent need to reduce any personal contact between people. Despite these major changes, e-government programs in many countries failed for many reasons, and the most important reason was the lack of acceptance for this system by the stockholders, so the rate of acceptance and use was one of the challenges troubling officials in the public sector. Previous studies have developed many theories and models to explore the most important factors that affect the acceptance and adoption of new technological systems such as e-government. However, these theories were often tested in developed countries and to a limited extent and less in developing countries such as Jordan. One of the most important and best models is the UTAUT model, which brings together many previous models and explains the acceptance of technology greatly compared to previous models. However, this model is still tested in different environments and does not cover all the factors that may affect the users' decision to adopt a new system, especially in the public sector. In this research, the model was expanded with additional variables related to trust and some features of the system that were not present in the original model and may be influential in the two countries (Jordan and Hungary) to study and explore the most important factors that affect the users' decision to adopt the e-government system. The results showed similar results in the two countries, so factors such as trust in the system and Performance expectancy are important and directly influence the users' adoption of e-government services in both countries. On the other hand, the differences came in the infrastructure axis, facilitating conditions influential in Hungary and less important and effective in Jordan. Moreover, the results showed that the factor effort expectancy is important and directly influencing the adoption of services in Hungary, but less important and influential in Jordan. Finally, The effect of the mediating variable in the study was variable, as the results showed that experience plays an important role. The relationship has changed in a positive way between the two variables Performance expectancy and the user's adoption in Hungary. However, in Jordan, this effect is limited to the relationship between effort expectancy and adoption; these differences in results were due to differences in the culture and level of awareness between the population of the two countries and other variables that could be discovered in the future studies to expand this study.