Requirements for Tax XAI Under Constitutional Principles and Human Rights

Tax authorities worldwide make extensive use of artificial intelligence (AI) technologies to automate various aspects of their tasks, such as answering taxpayer questions, assessing fraud risk, risk profiling, and auditing (selecting tax inspections). Since this automation has led to concerns about the impact of non-explainable AI systems on taxpayers' rights, explainable AI (XAI) technologies appear to be fundamental for the lawful use of AI in the tax domain. This paper provides an initial map of the explainability requirements that AI systems must meet for tax applications. To this end, the paper examines the constitutional principles that guide taxation in democracies and the specific human rights system of the European Convention of Human Rights (ECHR), as interpreted by the European Court of Human Rights (ECtHR). Based on these requirements, the paper suggests how approaches to XAI might be deployed to address the specific needs of the various stakeholders in the tax domain.