Research background and purpose:
The aim of this article was to determine the role of transnational corporations in shaping the global economy and to determine the level of their internationalization.

Design/methodology/approach:
In the analyzed case, the statistical method was used as the research method. The data obtained from UNCTAD formed the basis for determining the degree of enterprise involvement abroad using the Transnationality Index. TNI allows for the determination of the degree of internationalization of an enterprise.

Findings:
The aim of this article was to indicate the role of transnational corporations in the globalization process and to determine the degree of involvement of these enterprises abroad using the internationalization index. Taking into account contemporary challenges and the increasing globalization of business processes, it is reasonable to expand the existing internationalization index with variables that significantly influence the shape and level of enterprise internationalization.

Value added and limitations:
In the analyzed case, the degree of companies' involvement abroad is confirmed by high enterprise internationalization indices. It should also be emphasized that the hypotheses posed have been verified, and the following dependencies should be noted: H1: the higher the value of the share of individual variables in the total value share of a given variable, the higher the internationalization index of the transnational corporation will be, H2: high values of individual variables do not necessarily mean a high degree of internationalization of the transnational corporation. The proposed index can be applied to any company that undertakes foreign activities. The advantage of this index is that internationalization is presented based on various groups of indicators, related to both demand and supply. However, this index also shows some inaccuracies. Companies from home countries, despite their different sizes and diversity, are treated equally. Due to the fact that companies from smaller countries are "forced" to internationalize faster due to the small domestic market, the comparison with companies from countries with a large domestic market is not very distinct. In addition to the above, it should also be noted that this model does not indicate the international activities undertaken by the company, but only refers to numerical values.