Key audit matters as insights into auditors’ professional judgement: evidence from the European Union

The European Union (EU) Regulation 537/2014 introduced the mandatory disclosure of Key Audit Matters (KAMs) within an auditor’s report, with the aim of increasing the informational value of these reports. Extant research, however, shows contrasting results as to whether KAM disclosure is providing relevant information to stakeholders. Moreover, concerns have been raised about unintended consequences from KAM disclosure, with respect to the process that leads to the issuance of the audit report. Using a sample of 6,164 firm-year observations for the period 2017–2021, related to 1,660 unique firms listed in all EU Member States, we find that the number of KAMs is positively associated with audit fees, audit report lags and the probability that an opinion different from the standard unqualified opinion is issued. Moreover, we document that both KAMs related to entity-level and account-level risks are positively associated with audit fees, whereas only entity-level KAMs drive the positive association with audit report lags and the issuance of a modified opinion. Our research speaks directly to EU legislators, the International Auditing and Assurance Standards Board, the US Public Company Accounting Oversight Board, and any other regulators around the globe that have mandated the disclosure of KAMs within audit reports.