Explore which audit firms audit the world’s largest listed companies, how long they have held those engagements, and how much companies pay for statutory audit services.
The audit of a major listed company is one of the most important gatekeeping functions in the capital markets.
Yet information about who audits which company, how long the auditor has been in place, and how much the engagement costs is often scattered across annual reports, regulatory filings and shareholder documents.
Big4News is now bringing that information together.
Our Who Audits? database tracks the external auditors of companies in major stock-market indices around the world, including the FTSE 100, S&P 500, DAX 40, CAC 40, ASX 200, Nikkei 225 and other leading benchmarks.
Each index page shows:
Company — the listed company included in the relevant index.
Auditor — the external audit firm responsible for the current statutory audit engagement.
Since — the first financial year for which the current audit firm held the external audit engagement, rather than the year in which shareholders formally approved the appointment.
Latest audit fee — the latest disclosed fee for audit services in the company’s most recent annual report, normally FY2025.
Currency — audit fees are presented in the principal currency used for each market to make comparisons within the index easier.
Where a company has changed auditor for FY2026, this is flagged so that a fee disclosed for the previous financial year is not incorrectly attributed to the incoming audit firm.
The objective is to provide a transparent reference point for understanding the structure of the global audit market: which firms dominate major indices, where auditor changes are taking place, how long major companies retain their auditors, and how audit fees differ across companies and markets.
Explore the audit market
Who Audits the FTSE 100?
See the external auditors of the UK’s largest listed companies, together with auditor tenure and the latest disclosed audit fees.
[Explore the FTSE 100 →]
Who Audits the S&P 500?
Explore which accounting firms audit the largest publicly listed companies in the United States.
[Explore the S&P 500 →]
Who Audits the DAX 40?
See the audit firms responsible for Germany’s leading listed companies.
Who Audits the DAX 40?
The DAX 40 includes many of Germany’s largest and most internationally significant companies, spanning industries including automotive, chemicals, financial services, technology, industrials and healthcare.
Who Audits the CAC 40?
Explore the auditors, engagement tenure and disclosed audit fees of France’s largest listed companies.
[Explore the CAC 40 →]
Who Audits the ASX 200?
See which firms audit Australia’s largest listed companies and how the market is divided between the Big Four and other audit firms.
[Explore the ASX 200 →]
Who Audits the S&P/TSX Composite?
Explore the external auditors of major Canadian listed companies.
[Explore the S&P/TSX Composite →]
Who Audits the Nikkei 225?
See which audit firms serve Japan’s largest listed companies.
[Explore the Nikkei 225 →]
Who Audits the Hang Seng?
Explore the auditors of major companies listed in Hong Kong.
[Explore the Hang Seng →]
Who Audits the Nifty 50?
See the external auditors of India’s largest listed companies.
[Explore the Nifty 50 →]
Big4News will continue expanding and updating this database as new annual reports, auditor appointments and financial disclosures become available.