Prof. Dr. Nicole Ratzinger-SakelMarket structure of the German auditing market

10 October 2025

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Prof. Dr. Nicole Ratzinger-Sakel

Prof. Nicole Ratzinger-Sakel, an expert in Auditing and Corporate Accounting, together with Prof. Annette Köhler (University of Duisburg-Essen), has published an article on the structure of the audit market in Betriebs-Berater, Issue 39.

The article analyzes the structure of the German audit market based on the transparency reports for 2023 and 2024 in accordance with Art. 13 of the Audit Regulation (AP-VO). The analysis draws on 73 reports for 2023 and 70 reports for 2024, as published by the German Chamber of Public Accountants (WPK).

The study reveals a continuing dominance of the Big Four audit firms (PwC, KPMG, EY, Deloitte). Notably, KPMG has overtaken EY for the first time in eleven years, primarily due to a significant decline in EY’s non-audit fees. While Deloitte reports an increase in audit engagements, the other Big Four firms record slight decreases in mandates but continue to achieve overall revenue growth.

Among the other firms, Forvis Mazars stands out with a substantial increase in audit engagements, mainly resulting from the merger of Forvis and Mazars at the end of 2023. At the same time, the downward trend in the number of published transparency reports and in the number of public-interest entity audits by cooperative and savings bank associations continues.

“Overall, the analysis confirms a largely stable yet highly concentrated market structure, with only moderate shifts outside the Big Four”, summarizes Prof. Ratzinger-Sakel.