Considering the analyzed literature and the conducted research, the goals of the research were achieved, ie the role of information technologies in modern business and their relevance and role and the impact of information systems in the tourism sector are presented. The notion of information system is defined, as well as the notion of Big data, and the application and interpretation of this data in the function of tourism is explained. Furthermore, the concept of ICT and its application in tourism as well as its application among tourists and tourism entities, ie tourist communities through DMO (destination destination management) and DMK (destination management company) and various forms of branding using wide online channels. Legislative regulation in tourism is necessary and imposes numerous contributions of tourist entities from the supply side as well as the manner of keeping records of tourists. Such regulation is presented through 3 laws that cover the tourism sector as well as taxes on products and services in tourism and hospitality. The backbone of the entire paper is the E-visitor, whose conceptual definition, general conditions of use and digital support to system users, as well as direct benefits for tourist boards and accommodation service providers, are presented in chapter 5 of this paper. Furthermore, an overview and analysis of the report on tourist traffic of Zadar County in the period from 2015 to 2020 based on the E-visitor system are presented. Differences in the number of arrivals and overnight stays have been noticed since 2017, which is considered relevant for the implementation of E-visitor. In the last chapter the attitudes of accommodation providers in Zadar County on the positive and negative effects of online guest registration via E-visitor and 11 TZ employees on their perception of E-visitor implementation among accommodation service providers were examined, determined and analyzed. The data obtained from the research are presented and interpreted, and finally conclusions and proposals based on the results of primary and secondary research are made and presented.