Deloitte, EY, KPMG, and PwC make up the world’s largest professional services firms — known as the Big Four.
They have a combined 1.5 million employees globally and generate billions of dollars annually through a range of consulting and accounting services.
After a pandemic-era boom in demand, consulting firms were hit by a sharp slowdown as clients reined in spending. Growth ticked up at all of the Big Four in their latest financial years, though the speed of growth remains modest compared to the double-digit rate of growth seen in the pandemic years.
Deloitte, EY, and KPMG all expanded their workforces, while PwC pulled back.
The professional services industry is also highly exposed to AI-driven transformation. AI is rapidly changing the type of work that consulting firms offer their clients and the talent they require to carry it out.
The largest players are now locked in a race — and investing billions — to demonstrate that they can deploy AI effectively in-house and guide clients through the same transition.
Financial results released by the Big Four across the year illustrate how these forces are playing out. Here’s where they stand.
Deloitte
The previous year, Deloitte’s revenue growth rate had dropped sharply from 14.9% to 3.1%, but annual revenue picked up at Deloitte in its 2025 financial year.
At the beginning of the period, Deloitte restructured its core business lines, cutting them from five to four. The firm was targeted by the Trump administration’s DOGE cost-cutting drive in February 2025, and had a number of its government contracts eliminated.
The firm expanded head count by 10,000 to 470,000 total employees — a 2% rise.
Fiscal year end: May 31, 2025
Global revenue: $70.5 billion
Revenue growth year over year: 4.8%
Revenue growth by category:
- Tax and legal: 5.4%
- Audit and assurance: 3.8%
- Consulting — strategy, risk, and transactions: 5.5%
- Consulting — technology and transformation: 4.7%
PwC
PwC recorded a slowdown in global growth for the third consecutive year — the only member of the Big Four to do so. The firm called the results a “solid performance in a challenging economic climate.”
PwC reduced its global head count by 5,600 across its 2025 financial year, reversing a goal established in 2021 under its previous leader, Bob Moritz, to grow its global workforce to around 400,000. It now has 364,000 employees.
Fiscal year end: June 30, 2025
Global revenue: $56.9 billion
Revenue growth year over year: 2.7%
Revenue growth by category:
- Tax and legal: 1.1%
- Assurance: 1.9%
- Advisory: 4.6%
EY
At EY, revenue growth remained level with the previous year, though the firm saw an uptick in its consulting business — up 5.2% compared to no growth the previous year. EY also reported strong demand for its AI-related services, with a 30% rise in revenues driven by work such as “enterprise-wide transformations” and “AI governance frameworks.”
After reducing head count the previous year, EY expanded its global employee total by 3.4% to a total of 406,206.
Fiscal year end: June 30, 2025
Global revenue: $53.2 billion
Revenue growth year over year: 4%
Revenue growth by category:
- Assurance: 3.5%
- Tax: 5.5%
- Strategy and transactions: 0.4%
- Consulting: 5.2%
KPMG
KPMG is the smallest of the Big Four, both in terms of the number of employees and annual revenue.
The firm’s annual growth was steady compared to the previous financial year. For the second consecutive year, KPMG’s tax revenues grew notably faster than those of its competitors — up 7.5% compared to around 5.5% at EY and Deloitte, and 1% at PwC.
In February, KPMG became the first of the Big Four to set up a legal division in the US.
KPMG expanded its global workforce by 1% to a total of 276,030 employees.
Fiscal year end: September 30, 2025
Global revenue: $39.8 billion
Revenue growth year over year: 5.1%
Revenue growth by category:
- Tax and legal: 7.5%
- Audit: 6%
- Advisory: 2.9%
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