The S&P/TSX Composite is the headline benchmark for the Canadian equity market and the broadest index in the S&P/TSX family. Its constituents span financial services, mining and materials, energy, industrials, technology, real estate, utilities and consumer businesses.
The table below provides a company-by-company view of the external audit market across the index. It can be sorted by company, sector, auditor, since and audit fee.
Data checked as of 30 September 2026. The dataset contains 217 S&P/TSX Composite constituents. Audit fees generally relate to the latest disclosed financial year and are presented in Canadian dollars.
S&P/TSX Composite Auditors
S&P/TSX Composite Audit Market Share
PwC is the largest auditor of S&P/TSX Composite companies, holding 75 of the 217 engagements, or 34.6% of the index.
KPMG audits 62 companies (28.6%), followed by Deloitte with 41 (18.9%) and EY with 34 (15.7%).
Outside the Big Four, Grant Thornton audits two companies, while Crowe MacKay, PKF O’Connor Davies and D&H Group each audit one.
Taken together, the Big Four audit 212 of the 217 companies in the S&P/TSX Composite, equivalent to 97.7% of the index.
Audit leadership varies sharply by sector
PwC’s overall lead is driven heavily by Canada’s materials sector, the largest sector in the S&P/TSX Composite dataset.
Of the 59 materials companies, PwC audits 26, compared with 18 for KPMG and 10 for Deloitte. EY audits only two, while three companies use firms outside the Big Four.
Energy looks different. KPMG leads with 16 of the 39 mandates, followed by PwC with 13. Deloitte and EY each audit five.
Financial services are more concentrated among Deloitte and EY. Of the 23 financial companies, Deloitte audits eight and EY seven, compared with five for KPMG and only three for PwC.
PwC also leads real estate, with seven of the 18 mandates, while KPMG dominates information technology, auditing five of the nine companies in that sector.
The sector breakdown shows that the overall rankings conceal very different competitive positions. PwC’s strength is particularly pronounced in materials, while KPMG leads energy and technology and Deloitte holds the largest share of financial companies.
PwC leads by audit fees as well as mandates
Big4News identified a numeric audit fee for 214 of the 217 companies.
Across those companies, disclosed audit fees total approximately C$1.26 billion.
PwC-audited companies account for approximately C$395 million, or 31.4% of the identified fee pool.
KPMG follows with around C$302 million, or 24.0%, while Deloitte accounts for approximately C$287 million, or 22.8% and EY for about C$264 million, or 21.0%.
The five companies audited outside the Big Four account for less than 1% of identified fees.
The fee distribution is therefore somewhat more balanced than the mandate count. PwC remains the largest firm, but its 34.6% share of companies falls to about 31% when measured by disclosed fees, while Deloitte and EY carry greater economic weight than their client counts alone suggest.
The scale of the largest engagements explains why mandate share alone does not fully capture competitive position. A relatively small number of major banks, insurers and multinational groups account for a disproportionate share of the audit-fee pool.
Long-standing relationships sit alongside recent auditor changes
For 202 of the 217 companies, Big4News was able to establish the first financial year in which the current auditor held the engagement.
Some audit relationships stretch back several decades. Among the longest verified relationships in the dataset are EY at Manulife Financial from FY1905, PwC at Imperial Oil from FY1934, EY at TransAlta from FY1947 and KPMG at TC Energy from FY1956.
At the same time, the Canadian audit market continues to move. Eighteen current engagements in the dataset began in FY2023 or later.
Recent appointments include Deloitte at National Bank of Canada, EY at BCE, PwC at OceanaGold, Deloitte at Orla Mining and Deloitte at TFI International.
About the data
The dataset reflects the 217 constituents of the S&P/TSX Composite at 30 September 2026.
All fees are shown in Canadian dollars. Where a company reports its audit fee in another currency, Big4News converts the amount using an issuer-specific disclosed basis where available or the applicable Bank of Canada exchange rate.
The dataset contains a small number of auditor transitions. In those cases, the table shows the current auditor, while the latest available fee may relate wholly or partly to the predecessor firm. Those cases are identified in the underlying research.
For a fuller explanation of how auditors, tenure and fees are researched, checked and standardised across the project, see Who Audits? Sources & Methodology.
Who audits the world’s largest companies?
Explore the Big4News Who Audits? hub, which maps the audit firms behind the world’s leading stock-market indices — including auditor tenure, audit fees and Big Four audit market share.