The Big Four—PwC, Deloitte, EY, and KPMG—stand as the largest players in the global accounting and consulting sectors. Together, they employ over 1.5 million professionals and generate billions in annual revenue, significantly influencing hundreds of industries worldwide.

In recent years, these firms have faced diverse challenges, including reduced demand post-pandemic, evolving regulatory requirements, and the pressing need to integrate artificial intelligence technologies. In 2024, two of the Big Four appointed new leaders tasked with steering their organizations through this dynamic landscape.

In July 2024, Mohamed Kande became the first African to lead a Big Four firm as PwC’s global chairman. Kande also marks a departure from tradition as the first PwC leader with a background in advisory services rather than auditing.

Born in Côte d’Ivoire, Kande moved to France at age 16 for his education. Joining PwC in 2011, he now oversees 370,000 employees worldwide. In a LinkedIn post, Kande shared the challenges he faced due to his heritage and emphasized the importance of diversity: “I strive to create opportunities for those who, like me, didn’t have them.”

PwC has had to navigate financial and reputational difficulties recently. Partner earnings declined, early retirements increased, and the company announced in October 2024 its first major layoffs since 2009, cutting 1,800 jobs. Additionally, PwC faces challenges in rebuilding trust in the Asia-Pacific region following scandals in Australia and China.

“The need for reinvention has never been more urgent,” Kande stated in PwC’s 2024 annual review.

Deloitte, the largest Big Four firm by both workforce (460,000 employees) and revenue, announced a major restructuring in 2024 to simplify services and reduce costs. The company is also investing in green hydrogen, anticipating the market to reach $1.4 trillion by 2050.

Joe Ucuzoglu assumed the role of Deloitte’s global CEO in January 2023, following his tenure as CEO of Deloitte US from 2019 to 2022. In March 2024, Deloitte revealed plans to modernize and streamline its core offerings into four categories:

1. Audit and Assurance

2. Tax and Legal Strategy

3. Risk and Transactions

4. Technology and Transformation

In 2024, Janet Truncale became the first woman to lead a Big Four firm as EY’s global CEO. Her career with EY began in 1991 as an intern, and she now oversees 400,000 employees amid significant internal restructuring.

Truncale’s “All In” strategy promotes unity and collaboration, critical after the failed attempt to split EY into two divisions. Beyond her professional role, she is active in organizations like UNICEF USA and Women’s World Banking.

Bill Thomas, CEO of KPMG since 2017, has focused on strategic leadership and growth. Under his tenure, KPMG launched a $5 billion digital strategy investment plan, and global annual revenue has grown by 45%, reaching $38.4 billion.

Thomas, a Canadian, previously served as KPMG’s Americas Chair and is known for staying out of the limelight, giving few interviews. He emphasizes the importance of STEM education, stating, “Technology permeates every aspect of our business and our clients’ operations.”

The smallest of the Big Four, KPMG employs 275,000 people and prioritizes technological innovation to remain competitive.