Purpose Supreme audit institutions (SAIs) examine and supervise the activity of public institutions. The study aims at contributing to the existing literature on public sector audit by providing a classification of 29 European SAIs - 28 national SAIs and the European Court of Auditors (ECA) - based on a broad range of attributes varying from the SAIs' environment to its structure, activity, resources or transparency. Design/methodology/approach The authors apply quantitative methodology for clustering by means of multidimensional scaling and regressive ordinary least square (OLS) and logistic models. Findings The authors' results show that SAIs from veteran EU member states (MSs) are more similar amongst them and the same applies to SAIs from Nordic countries, Baltic countries, Western Mediterranean countries and Eastern countries. The authors also perform additional analysis focussing on currently relevant issues such as gender equality, age, environment or the sustainable development goals (SDGs), concluding that the younger the institutions' staff, the more transparent the institutions are. The authors also find that more transparent SAIs report on environmental audits, more prone to cover the SDGs in their audits. Research limitations/implications The research is limited in purpose and scope because data cover only Europe. Given the limited number of observations (29), it does not have prospective purposes but only explanatory ones. The authors' findings are interesting for researchers because they offer original insights on public audit in Europe and cover matters of current interest such as environment, transparency or gender equality. Practical implications The research is also of interest for public auditors because it offers them information that may help them improve their activity and find institutional synergies, as the dataset is available to public auditors. Social implications From a social view point, the paper shows that public auditors perform work on topics of interest for the citizens. Originality/value The dataset compiled for the research offers extensive data and a wide variety of attributes defining European SAIs and may offer future opportunities for research from different perspectives.
