How the Big Four are shaping AI Auditing

Publié le 28/07/2025

In the face of the rapid rise of artificial intelligence (AI) in financial processes, the audit and consulting giants—Deloitte, EY, PwC, and KPMG—are positioning themselves as strategic players in a new market: the auditing and certification of AI models, also known as AI assurance. This initiative stems from growing demand by companies eager to demonstrate to their clients, partners, and regulators that the AI tools they deploy are reliable, transparent, and compliant with ethical and legal standards.

In the face of the rapid rise of artificial intelligence (AI) in financial processes, the audit and consulting giants—Deloitte, EY, PwC, and KPMG—are positioning themselves as strategic players in a new market: the auditing and certification of AI models, also known as AI assurance. This initiative stems from growing demand by companies eager to demonstrate to their clients, partners, and regulators that the AI tools they deploy are reliable, transparent, and compliant with ethical and legal standards.

The Big Four at the Forefront of Structuring AI Auditing

According to the Financial Times, Deloitte, PwC, and EY are already developing dedicated AI audit services, while KPMG is also exploring this avenue. The principle is to apply to the technological domain the same rigor and methodology that have historically defined these firms in financial auditing. Richard Tedder, a partner at Deloitte, emphasizes how crucial these new assignments have become to support the widespread adoption of AI in critical sectors such as healthcare and finance, where even minor algorithmic bias can have serious consequences. PwC UK has announced the imminent launch of a comprehensive AI assurance service, while EY highlights the technical complexity of the task: as models constantly evolve, it is difficult to guarantee a completely fixed audit.

This still nascent market attracts attention due to the absence of an internationally recognized regulatory framework. Today, many AI tools are “validated” by the companies that develop them, raising concerns about independence and credibility. The Big Four leverage their reputation to offer an objective and structured guarantee, comparable to the assurance they already provide on non-financial data and ESG commitments. According to estimates cited by CFO Economic Times, this activity could eventually represent a significant share of their revenues, addressing both market needs and increasing regulatory pressure.

Technical Challenges and Implications for Finance Departments

In practice, these AI audit services primarily focus on examining the processes and governance surrounding the models: how they are trained, what data is used, and what internal controls are in place to prevent drift or bias. Less frequently, they assess the algorithm itself, due to its technical complexity and evolving nature. As EY’s Pragasen Morgan notes, it is currently premature to envision a “total” and fixed certification of an AI model, as it can change over time.

For finance departments, this evolution carries significant consequences. They will need to integrate new dimensions into their control practices: data quality and traceability, model robustness, and operational risks related to automated decisions. This transformation also requires adapting internal skills, collaborating more closely with data scientists and experts in algorithmic governance.

Towards a New Era of Trust and Regulation Around AI

Beyond the technical aspect, this trend reflects a broader movement: auditing reinventing itself to fit the contours of a data- and AI-driven economy. The Big Four understand that their future depends on their ability to combine financial expertise, risk knowledge, and an understanding of disruptive technologies. Regulators, too, are beginning to work on defining standards to harmonize practices and prevent each player from building its own frameworks.

In this rapidly growing context, AI auditing is no longer science fiction but is already becoming a key lever of trust and competitiveness for companies. For the financial sector, the revolution is underway: it demands vigilance, adaptation, and anticipation. The challenge is significant, but the opportunity is vast.

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