The global consulting landscape, dominated by Deloitte, EY, KPMG, and PwC—collectively known as the Big Four—underwent notable changes throughout 2025. These professional services giants, which employ a combined workforce of approximately 1.5 million people worldwide and generate tens of billions in annual revenue, faced a deceleration in growth relative to the robust expansion witnessed during the pandemic years.
Following an intense surge in demand for consulting services during the height of the pandemic, these firms saw a pronounced decrease in client spending adjustments, resulting in more tempered growth rates. This trend was visible across all four firms, each reporting subsequent annual revenue increases, albeit at a substantially lower pace compared to the double-digit expansions recorded previously.
A significant industry-wide shift driving both challenges and opportunities is the rapid advancement and adoption of artificial intelligence (AI). This technological evolution is reshaping the consulting service offerings and transforming the skill sets demanded from their workforce. To remain competitive, the Big Four have committed substantial investments to both deploy AI internally and assist their clients in navigating AI-enabled transformations.
Deloitte's Financial and Operational Overview
Deloitte experienced a rebound in revenue growth in its 2025 financial year after a steep decline the prior year from 14.9% to 3.1%. The firm recorded a year-over-year increase in global revenue of 4.8%, culminating in $70.5 billion. At the onset of this fiscal period, Deloitte restructured its principal business units, reducing them from five to four segments to streamline operations.
Despite this internal reshuffling, the firm faced external pressures such as cost-cutting measures from the Trump administration under the DOGE program in February 2025, which led to the elimination of several government contracts. On the human resources front, Deloitte expanded its employee base by 10,000, bringing its total workforce to 470,000, reflecting a 2% growth.
Revenue growth was diversified across service categories. Tax and legal services grew 5.4%, audit and assurance increased by 3.8%, consulting around strategy, risk, and transactions saw a 5.5% rise, and consulting focused on technology and transformation achieved a 4.7% increase.
PwC’s Performance amid Workforce Contraction
Contrasting its peers, PwC encountered a continued slowdown, marking the third consecutive year of reduced global growth. Despite this trend, the firm described its financial results as a "solid performance in a challenging economic climate." PwC's revenue for the fiscal year ending June 30, 2025, totaled $56.9 billion, reflecting a modest 2.7% year-over-year increase.
In a notable strategic pivot, PwC reduced its global headcount by 5,600 employees across the year, reversing an earlier objective set in 2021 under former leadership to grow the workforce to roughly 400,000. Currently, their employee base stands at 364,000.
Revenue growth across PwC's service lines varied: tax and legal activities increased by only 1.1%, assurance services by 1.9%, while advisory services experienced a more robust rise of 4.6%.
EY's Steady Growth Driven by Consulting and AI Services
EY's overall revenue growth remained stable with the previous fiscal year, totaling $53.2 billion for the period ending June 30, 2025, which corresponds to a 4.0% increase year-over-year. Notably, EY's consulting segment experienced an uplift, growing 5.2% compared to flat growth in the preceding year.
Demand for AI-related services proved to be a significant growth driver for EY, evidenced by a 30% surge in revenue from projects such as enterprise-wide transformations and the development of AI governance frameworks. This emphasis reflects the firm's strategic initiative to integrate AI services into its broader consulting practice.
The firm’s workforce expanded by 3.4%, adding employees after a reduction the previous year, bringing the total headcount to 406,206.
Breaking down revenue growth by category, assurance services increased by 3.5%, tax services led at 5.5%, strategy and transactions saw minor growth of 0.4%, and consulting services rose 5.2%.
KPMG's Consistent Growth and Innovation in Legal Services
KPMG maintained steady performance in its 2025 financial year, with a 5.1% increase in annual revenue to reach $39.8 billion. Although it is the smallest of the Big Four by both revenue and headcount, KPMG recorded notable advances, particularly in its tax segment, which expanded by 7.5%, outperforming competitors such as EY and Deloitte, which posted approximately 5.5% growth in this category, and significantly surpassing PwC's 1.1% growth.
In February 2025, KPMG distinguished itself by becoming the first among the Big Four to establish a legal division in the United States, a strategic move to broaden its service offerings. The firm also increased its global workforce by 1%, totaling 276,030 employees.
The detailed growth by revenue category for KPMG includes 7.5% in tax and legal services, 6% in audit, and 2.9% in advisory services.
Industry Trends and Challenges
The shared trajectory for the Big Four firms encapsulates a transition from the intense growth during the pandemic to more moderate advancement, influenced by economic challenges and shifting client demands. Workforce changes varied, with three firms opting to grow their employee base while PwC took the opposite approach.
The integration of AI stands as a pivotal factor influencing these firms' strategic directions. With billions invested in AI capabilities to transform internal operations and client-related services, consultancy firms are adapting their talent acquisitions and service portfolios to meet evolving technological and market needs.
This period of recalibration reflects both the opportunities and uncertainties faced by the professional services sector as it navigates economic headwinds and rapid technological shifts.