Deloitte, EY, KPMG, and PwC make up the Big 4 — here’s how they compare

Deloitte, EY, KPMG, and PwC are the world’s largest accounting and consulting firms, known as the Big Four.

With histories dating back to the 19th century, they have grown into billion-dollar companies employing hundreds of thousands of staff who earn high salaries and often work very long hours.

The Big Four offer companies services such as workforce transformations, reshaping corporate finance portfolios, assurance, valuation, and optimizing the use of technology.

Put simply, they’re there to assess businesses and tell them how to run more efficiently.

The pandemic changed the landscape for the major firms, with a surge in demand that sparked a hiring boom. The Big Four are now attempting to balance operations amid slowing demand.

Here’s a look at where the Big Four stand.

EY

After a series of mergers, EY was formed in 1989 as the accountancy firm Ernst & Young. It has since diversified its offerings and, in 2013, rebranded to EY.

Headquartered in central London, EY has more than 700 offices in 150 countries. Janet Truncale, the global chair and CEO, took over from Carmine Di Sibio in July.

EY focuses heavily on consultancy and assurance but also covers tax and strategy, and transactions.

EY has been praised for its approach to diversity. 

Revenue was up 3.9% on the previous year to $51.2 billion, according to the firm’s latest annual report published in October. It was EY’s poorest performance since 2010. Assurance services were its largest revenue generator.

In May 2024, the firm was caught up in a scandal along with PwC and fined $11.7 million by UK authorities for a series of auditing failures.

As pressure has mounted, EY cut UK partner payouts by 5% and laid off employees. Overall employee numbers dropped by 2,450 during EY’s latest financial year — the first decrease in 14 years.

EY’s global head count now stands at about 393,000.

In 2023, the firm launched EY.ai, an AI platform aiming to assist clients across all its professional services. It also offers clients a conversational AI assistant called EYQ.

Deloitte

Deloitte is the largest of the Big Four by both revenue and employees.

Founded in the UK in 1845, Deloitte expanded into the US in 1890. It is headquartered in London and has more than 700 offices in some 150 countries. It’s known for strong business and technology consulting services.

Joe Ucuzoglu has been its global CEO since 2022.

In March, Deloitte announced a major restructuring aimed at cutting costs and repositioning it for future success.

It is “modernizing and simplifying” its core offering into four categories: audit and assurance, tax and legal strategy, risk and transactions, and technology and transformation.

Deloitte Global CEO Joe Ucuzoglu. 

Global revenue climbed 3.1% to $67.2 billion in the 2024 financial year, but, like EY, that performance was far lower than the 14.9% growth in 2023.

The slowdown has affected partner payouts, which fell by 4.5% to about $1.27 million. Equity partners took home roughly $63,000 less than they did a year ago.

Deloitte’s global workforce expanded to 460,000 in 2024, an increase of 3,000.

Deloitte has pledged to invest $3 billion in AI by fiscal year 2030 and has partnered with technology industry leaders Nvidia, Google Cloud, and AWS to develop its client offering.

PwC

PwC is often considered the most prestigious of the Big Four, and topped the latest Vault Accounting 25 ranking.

Officially formed in 1998 from a merger between Price Waterhouse and Coopers & Lybrand, PwC’s headquarters is almost opposite EY’s main office in London.

Mohamed Kande has been the global chairman since July.

PwC has three core lines of business — assurance, advisory, and tax and legal services — but the firm is particularly known for its strong and well-established audit client base.

It employs more than 370,000 people in 149 countries and territories.

In 2021, PwC committed to creating over 100,000 net new jobs over a five-year period, and in October 2024, it said it had already hit three-quarters of that target.

PwC hit record-high revenues in the financial year 2024. 

PwC was the second-highest earning of the Big Four, posting record gross revenue of $55.4 billion and 3.7% annual growth in the year to June 30.

Though not as stark a slowdown as Deloitte or EY, growth at PwC still dropped noticeably compared to the 9.9% rise reported for the previous 12 months.

A number of high-profile scandals in the Asia-Pacific region involving its work with the Australian and Chinese governments damaged business.

To handle the changing environment, PwC cut partner pay by 5%, leaving partners taking home an average of $1.09 million this financial year.

In October The Wall Street Journal reported that the firm would make its first major layoffs since 2009 and cut 1,800 jobs.

PwC has invested $1.5 billion to expand and scale its AI capabilities. In February 2024, it unveiled a tax AI assistant for 2,300 PwC tax professionals in the UK to use.

KPMG

The smallest of the Big Four in terms of revenue and employees, KPMG is headquartered in Amsterdam and has a long-serving leader in chairman and chief executive Bill Thomas.

Its core services cover audit, tax and legal, and advisory.

The last of the Big Four to report its 2024 results, KPMG reported in December that in the 12 months to September 30, it saw revenues of $38.4 billion, a rise of just over 5% compared to 2023.

Overall, its revenues are the lowest among the Big Four, close to $20 billion less than its three competitors.

KPMG is lagging behind its three major competitors.

KPMG has faced scrutiny across several markets for its auditing and accounting work. In 2023, it was fined a record $26 million in the UK after “exceptional” failures in its accounting work.

Employee numbers grew by just over 1% in the 2024 financial year to reach 275,000. That’s 185,000 people fewer than Deloitte.

Over 2024, KPMG has made a series of layoffs. About 330 staff, or 4%, were cut from its US audit practice; 5% cut across advisory, tax, and back-office functions; and 2% from its advisory workforce in 2023, according to Accountancy Age.

KPMG said it is looking to invest more in specialist roles in areas like ESG, tax, and technology.

While it lags behind in revenues, the firm is seen to foster a less cutthroat workplace than its competitors. The firm has said it aims to have women in a third of partner or director roles by 2025.

According to its latest report, women hold 29.9% of leadership roles.