The Hang Seng Index is Hong Kong’s flagship equity benchmark, spanning many of the largest companies traded on the Hong Kong Stock Exchange.
Following the September 2026 index review, the Hang Seng has 95 constituents, up from 93 after the addition of Hua Hong Semiconductor and Weichai Power. Hang Seng Indexes says the enlarged index represented 64.9% of the market value of its eligible universe as of 30 June 2026 and 54.9% of second-quarter turnover.
It is also distinctly cross-border. The current index comprises 23 Hong Kong companies, 42 companies classified by Hang Seng Indexes as “other Mainland companies”, 22 H-share companies and eight red chips.
That composition is reflected in its audit market. Hong Kong and mainland Chinese audit entities frequently sit within the same international networks, while a small number of local and mid-tier firms retain mandates among the blue-chip constituents.
The table below shows the current auditor of every Hang Seng constituent, the first financial year of the current audit engagement where this could be established, and the latest audit fee identified.
It can be sorted by company, sector, auditor, since and audit fee.
Data checked as of 30 September 2026. Audit fees are shown in Hong Kong dollars.
Hang Seng Audit Market Share
The Big Four audit almost 93% of the Hang Seng
The audit market at the top of the Hong Kong stock market is highly concentrated.
EY and Deloitte are tied for the largest number of Hang Seng audit mandates, with 25 companies each, equivalent to 26.3% of the index apiece.
PwC audits 20 companies, or 21.1%, while KPMG audits 18, or 18.9%.
Together, the Big Four audit 88 of the Hang Seng’s 95 constituents — 92.6% of the index.
The remaining seven companies are divided among five non-Big Four firms.
Grant Thornton audits Geely Automobile and CATL.
SHINEWING (HK) audits China Hongqiao and Orient Overseas International.
HLB Hodgson Impey Cheng audits Haier Smart Home
Forvis Mazars audits Tingyi
Confucius International CPA Limited audits Sinopharm Group.
Concentration is particularly pronounced at the blue-chip end of the market
The Hang Seng figures also provide an interesting contrast with developments across Hong Kong’s wider listed-company audit market.
Hong Kong’s Accounting and Financial Reporting Council has found that the share of listed-company audit engagements held by its largest category of audit firms has been declining.
Category A firms — defined by the regulator as firms auditing at least 100 listed companies — accounted for 62.1% of engagements in 2022, down from 73.0% in 2018, while the share held by Category B firms increased from 18.6% to 30.2%. Category A is a regulatory size classification rather than another name for the Big Four.
At the very top of the market, however, the Hang Seng data shows that concentration remains much stronger: fewer than one in 13 constituents is audited outside the Big Four.
That is consistent with an earlier AFRC study, which found particularly high concentration among Hong Kong’s largest listed entities. In 2019, four of the largest audit firms audited all but two of the 105 locally audited listed companies with market capitalisations above HK$50 billion.
EY has a particularly strong position among the Hang Seng’s financial companies
The overall market-share numbers conceal significant differences between sectors.
Of the ten financial companies in the Hang Seng, seven are audited by EY: China Construction Bank, ICBC, Bank of China, Ping An Insurance, China Life Insurance, China Merchants Bank and BOC Hong Kong.
The remaining three are divided between PwC, which audits HSBC, and KPMG, which now audits AIA Group and Hong Kong Exchanges and Clearing.
The technology segment looks different. PwC audits Tencent, Xiaomi, NetEase and Lenovo, while EY audits SMIC, Hua Hong Semiconductor and BYD Electronic, and Deloitte audits Sunny Optical.
The Hang Seng therefore does not have a single dominant Big Four firm across the entire index. Leadership changes substantially by sector.
Some audit relationships extend back more than two decades
Another striking feature of the data is the length of some audit relationships.
PwC’s engagement with Alibaba dates to 1999.
KPMG has audited the current MTR Corporation since 2000.
EY has audited Sino Biopharmaceutical since its first listed financial year in 2000.
Deloitte’s engagement with ENN Energy dates to 2001.
PwC’s with NetEase to 2002.
PwC has audited Trip.com Group since 2003.
Hong Kong does not impose a general mandatory rotation period on the audit firm of a listed company. Auditor changes are generally voluntary, although independence rules include rotation requirements for key audit partners and staff. Listed issuers appoint their auditor annually, and their audit committees are expected to monitor the auditor’s independence.
That framework permits audit-firm relationships to continue for considerably longer than in jurisdictions that impose mandatory firm rotation.
But there has also been a significant amount of recent movement
Long tenure does not mean the Hang Seng audit market is static.
At 20 of the 95 companies, the current auditor’s first financial year is 2024 or later.
Among the most recent changes, KPMG took over the audits of AIA Group and Hong Kong Exchanges and Clearing for FY2026. Deloitte became auditor of China Resources Land for FY2026, while KPMG began its first full audit year at Link REIT in 2026.
Several major mainland financial institutions also have relatively recent auditor appointments. EY became auditor of ICBC, Bank of China, China Life Insurance, China Merchants Bank and BOC Hong Kong from FY2024.
The AFRC has separately reported elevated auditor switching across Hong Kong’s wider listed market: more than 10% of listed entities changed auditor in both 2023 and 2024. Around one-third of those changes involved a move from a larger auditor category to a smaller one.
That broader trend is not yet strongly reflected at Hang Seng level, where the overwhelming majority of mandates remain with the Big Four.
Audit fees range from a few million dollars to more than HK$800 million
An audit-fee figure was identified for every company in the dataset.
The median is approximately HK$15.8 million, although comparisons need to be treated with care because companies do not always define their disclosures identically. Some report a narrowly defined statutory audit fee, while others include audit-related or closely associated assurance work.
The largest amount in the dataset is HSBC’s HK$849.1 million.
Other large disclosed amounts include:
CK Hutchison Holdings — HK$332.0 million
AIA Group — HK$216.7 million
ICBC — HK$208.4 million
Bank of China — HK$207.3 million
Tencent Holdings — HK$187.7 million
Ping An Insurance — HK$184.4 million
China Construction Bank — HK$153.8 million
CITIC — HK$146.2 million
Alibaba Group — HK$128.9 million
AIA requires a qualification: KPMG is the current FY2026 auditor, but the HK$216.7 million fee shown in the table relates to the FY2025 audit performed by predecessor PwC. The same timing issue affects Hong Kong Exchanges and Clearing, where the latest fee relates to PwC despite KPMG’s FY2026 appointment, and China Resources Land, where the latest disclosed fee relates to predecessor KPMG rather than incoming auditor Deloitte.
About the data
Auditor identifies the current external auditor as of the late-September 2026 dataset.
For Big Four firms, Big4News uses the global network name — Deloitte, EY, KPMG or PwC — to make the table comparable across companies. The legal entity signing an audit report can differ according to where the issuer and engagement are based. A mainland Chinese company, for example, may be audited by the mainland member firm of a global network rather than its Hong Kong member firm.
Non-Big Four firms are shown by their individual firm names.
Since refers to the first financial year for which the current auditor held the external audit engagement, rather than the year in which shareholders subsequently voted to reappoint the firm.
Where the exact starting year could not be established from sufficiently strong evidence, the field has been left blank. Big4News does not infer an exact starting date simply because an auditor can be demonstrated to have held the engagement by a particular historical year.
Audit fee is the latest identified amount paid for statutory audit or audit services. Non-audit services are excluded where the issuer provides sufficient information to separate them.
Where the disclosure combines audit with closely related assurance or review work and no narrower figure is available, the broader audit-related amount may be used and identified in the research notes.
Amounts originally reported in currencies other than Hong Kong dollars have been converted into HKD on the consistent basis used for this dataset.
Where an auditor changed for FY2026 but the most recent available fee relates to the outgoing auditor, the figure is retained as the latest disclosed audit fee rather than being attributed to the incoming firm.
Research was checked primarily against annual reports, independent auditor reports, AGM documentation, HKEX filings, SEC filings where applicable, and other company and regulatory sources.
Data checked as of 30 September 2026.
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.