Background:  The introduction of the EU-taxonomy for sustainable activities in 2020 aims to create a shift in investments to foster sustainable growth. It classifies an organisation as “green” or not based on a predetermined set of categories and criteria. However, not all organisations are included. Small to medium enterprises are not included, and do not need to report on their activities. However, there exist SMEs which decided to still, to the extent possible, voluntarily comply with the EU-taxonomy. This form of voluntary compliance has not been explored in the prior literature.    Purpose:  The purpose of this study is to investigate the “Why” and the “How” of SMEs voluntarily compliance with the EU-taxonomy sustainability regulation.   Method:  In order to fulfil the purpose an interpretive qualitative approach has been adopted in this study. A comparative case study is used to develop an understanding of the individual cases but also their comparative aspects through a cross analysis. The information from the cases was collected through semi-structured interviews as well as from secondary data such as annual reports.    Conclusion:  This study concludes that while there are a multitude of reasons why an SME voluntarily complies to the EU-taxonomy, such as reputation and environment. “How” an organisation voluntarily complies is highly dependent on the industry and resources of an organisation.