The datasets included in this article come from a survey carried out on a group of Polish students and self-employed entrepreneurs and were originally created for studies on tax behaviour under the slippery slope framework. The slippery slope framework explains the role of extensive power execution and building trust in the tax administration in enhancing either enforced or voluntary tax compliance accordingly[1]. Students of economics, finance, and management at the Faculty of Economic Sciences and the Faculty of Management at the University of Warsaw were surveyed in two rounds, in 2011 and 2022, using paper-based questionnaires handed to them personally. Entrepreneurs were invited to fill in online questionnaires in 2020. Questionnaires were filled in by self-employed individuals from the Kuyavia-Pomerania, Lower Silesia, Lublin, and Silesia Province. The datasets provide 599 records for students and 422 observations for entrepreneurs. The purpose of collecting these data was to analyse the attitudes of the mentioned social groups towards tax compliance and tax evasion under the slippery slope framework along two dimensions: trust in authorities and power of authorities. The sample was selected because students in these fields are the most likely to become entrepreneurs, so the study sought to capture the potential behavioural change that is taking place. Each questionnaire consisted of three parts, a description of a fictitious country (Varosia) in one of four scenarios: (1) high trust-high power; (2) low trust-high power; (3) high trust-low power; (4) low trust-low power, 28 questions including manipulation checks on trust in authorities and power of authorities, intended tax compliance, voluntary tax compliance, enforced tax compliance, intended tax evasion, tax morale and the perceived similarity between Varosia and Poland, and finally two questions on gender and age of respondents. The data presented are particularly useful for policymakers in shaping tax policy and economists in analyses regarding taxation. Researchers may be interested in reusing the provided datasets for comparative research in other social groups, regions, and countries.