Purpose: This paper compares Corporate Sustainability Reporting Directive (CSRD) implementation in Slovenia and Montenegro, building on their 2017 Non-Financial Reporting Directive (NFRD) transposition. It also examines their responses to CSRD’s expanded assurance requirements. Methodology/research approach: A qualitative descriptive approach will analyze relevant pronouncements (i.e., directives, laws, and proposed laws) using comparison and synthesis to assess harmonization with the CSRD directive, with special attention given to assurance requirements in sustainability reporting. Findings: Slovenia has fully transposed the CSRD, while Montenegro is still at the draft law stage, revealing regulatory gaps linked to its EU integration status. Research limitations/implications: The research excludes empirical data and stake-holder opinions but contributes to the emerging literature on Central and Eastern Europe (CEE) countries. Practical implications: This study highlights regulatory gaps in Montenegroʼs proposed Law of Accounting, guiding future alignment with the CSRD on sustainability assurance. Originality/value: To the best of our knowledge, this is the first study to examine the transposition of the CSRD in the context of both an EU Member State and a candidate country. It bridges a literature gap and offers valuable insights into the normative differences and implementation challenges between Slovenia and Montenegro.
