The Big Four accounting and consulting firms—Deloitte, PwC, EY, and KPMG—have long dominated the global professional services industry, Business Insider reports.
Their extensive reach, deep expertise, and comprehensive service offerings make them indispensable to many large corporations. However, advances in artificial intelligence (AI) are now posing challenges that could disrupt not only job roles but also the Big Four’s organizational structures, business models, and pricing strategies.
AI-driven automation is expected to transform core service lines such as audit, tax, and advisory. Alan Paton, former PwC partner and now CEO of AI consultancy Qodea, predicts that up to half of roles in these structured, data-intensive areas could be automated within the next three to five years. AI tools are already capable of completing 90% of audit tasks, raising questions about the value proposition of traditional consulting fees when clients can receive instant answers from automated systems.
This shift may force the Big Four to specialize further or risk losing ground as clients increasingly expect faster, cheaper, and more technology-enabled solutions. Yet some industry voices believe AI will enhance consultants’ productivity rather than replace them. Casey Foss, chief commercial officer at midsize consultancy West Monroe, emphasizes that human expertise remains essential to interpret AI outputs and apply nuanced judgment.
The Big Four’s traditional reliance on billable hours and labor arbitrage—offshoring junior-level work to lower-cost markets—could be challenged by AI’s ability to deliver services remotely and more efficiently. If AI can perform tasks that previously required large, geographically dispersed teams, firms anchored to such models may face declining revenues and difficulty adapting.
Moreover, the growing preference for outcomes-based pricing rather than hourly billing threatens established revenue structures. Foss notes that large firms must balance upskilling staff, redesigning services, and maintaining agility—a complex task for organizations of their size.
Smaller and mid-market consultancies see AI as a catalyst for growth and competitiveness. By automating routine work, these firms can overcome limitations like smaller talent pools or less sophisticated internal tools. Alibek Dostiyarov, CEO of AI startup Perceptis, explains that AI enables smaller firms to manage more projects simultaneously and improve responsiveness.
West Monroe, for example, reports a surge in new talent from former Big Four professionals attracted by the agility of mid-sized firms and their innovative use of technology. This shift suggests that AI could help level the playing field and intensify competition within the sector.
Despite the challenges, the Big Four possess significant advantages in scale, investment capacity, and sector knowledge. They have committed billions to AI and cloud technology, aiming to develop integrated, enterprise-grade solutions for clients worldwide. KPMG’s $2 billion AI investment plan, projected to generate $12 billion in revenue over five years, exemplifies this approach.
Executives at EY and KPMG argue that their size allows them to manage the complexities of AI implementation, including risk, compliance, and ethical considerations, more effectively than smaller firms. Raj Sharma, EY’s global managing partner for growth and innovation, highlights the firm’s century-long sector experience combined with its large professional workforce as key strengths in adapting to AI-driven change.
PwC’s chief technology officer, Umang Paw, emphasizes the firm’s decade-long engagement with AI and its collaboration with technology partners to embed AI in client services. He sees AI as a transformative force reshaping professional services, continuing a historical pattern seen in previous industrial revolutions.
