The study examines the causal relationship between the level of IoT adoption in tourism services and trust in these systems, on the one hand, and individual internal consumer behaviours, on the other. Influencing factors are grouped into six categories: awareness, confidentiality and safety, cost, convenience, social influence, and habits. Each category is described by several items, and the correctness of their aggregation is tested with the Cronbach's alpha coefficient. The dependent variable is defined on an ordinal scale, to be able to progressively evaluate the degree of IoT adoption. The research methodology uses the ordered multinomial logit model, applied to a database of 431 tourists from Romania. The main results show the significant influence of behavioural variables related to awareness, convenience, habits, and cost. Among the socio-demographic factors, the role of age and education was highlighted. The conclusions of the study make policy recommendations necessary for the development of IoT systems in tourism industry.