The study aims to examine trends in the integration of artificial intelligence within the operational processes of tax administrations across the Member States of the European Union. It explores both the functional domains in which AI can be deployed and the institutional, ethical, regulatory and technological constraints that shape its deeper integration. The analysis relies on publicly available data from the Organisation for Economic Co-operation and Development (OECD), complemented by information from other open sources. Based on this dataset, the study develops a Tax AI Index (TAI) to provide a comparative quantitative assessment of the extent to which AI systems have been operationally integrated into EU tax administrations. The index is constructed from four subindices capturing (1) the use of artificial intelligence in communication between tax administrations and economic agents (TAIIS); (2) the integration of artificial intelligence in data management systems (TAIDS); (3) the application of algorithmic systems in tax enforcement, compliance control and administrative decisions (TAIRES); and (4) mechanisms for accountability, transparency and ethical oversight in the use of artificial intelligence (TAIGS). The empirical results indicate significant heterogeneity in the levels of digital transformation among the EU-27 Member States. In most countries, the adoption of artificial intelligence remains at an experimental or pilot stage, suggesting that its broader operational application is still evolving. To place these findings in a broader context, the analysis is complemented by an external measure of digital government development, allowing for a comparative assessment between AI adoption in tax administrations and overall public sector digital maturity.
Angel Angelov (Sun,) studied this question.