Has GenAI become core to accountancy?

The mood around AI in accountancy has changed. A year ago, firms looked at generative AI with caution. Now, they are embracing it more freely. New research from Thomson Reuters shows that 79% of tax and accounting firms expect “significant” GenAI integration by 2027. This really shows that the industry isn’t vague about its future usage of AI – it’s actively making plans that include it.

Last year, just over half thought AI should be used in daily work. Now it’s 71%. Firms aren’t experimenting anymore – they’re embedding it. The number of tax firms already implementing GenAI has jumped from 8% to 21% in just one year. Another 25% say they’re next.

For some, GenAI is already part of the core. Some 13% of professionals say it’s central to how they work. A third expects full integration within 12 months. Another third say within two years. The pace is clearly accelerating.

Elizabeth Beastrom, president of tax and accounting professionals at Thomson Reuters, has seen the shift up close. “What we’re witnessing is a transformation in how tax, audit and accounting professionals view AI technology,” she said. “This surge in adoption positions the accounting profession as one of the fastest-growing industries for GenAI acceptance among professional services.”

Accounting firms have moved beyond debating whether generative AI has a role in their operations. The central question has shifted to the extent and speed at which this technology will transform the accounting profession.

A year can change everything, as Thomson Reuters’ data clearly shows. Firms have seen real productivity gains from using this technology. But it isn’t just internal momentum that’s forcing the shift. The pressure is now coming from clients.

The technology is no longer framed as a risk to jobs; only 9% of professionals see GenAI as a threat to employment. Most now see it for what it is: a tool to sharpen expertise, not replace it.

“Where previously clients might have viewed technology adoption as an internal efficiency matter for firms, they’re now explicitly demanding it as part of service delivery,” Beastrom says. “They clearly see the technology as a competitive differentiator. They’re increasingly expecting the efficiency gains and innovative approaches that GenAI enables, making adoption not just a nice-to-have but a business imperative.”

Competition is also accelerating the pace. More firms are making strategic investments in GenAI – and others are following suit to avoid being left behind.

“The dramatic shift in attitudes toward GenAI among professionals reflects a perfect storm of factors converging over the past year,” Beastrom adds. “Professionals experience tangible productivity benefits firsthand, which has transformed scepticism into enthusiasm.”

The technology is no longer framed as a risk to jobs; only 9% of professionals see GenAI as a threat to employment. Most now see it for what it is: a tool to sharpen expertise, not replace it.

According to Thomson Reuters’ latest research, 77% of corporate clients want their tax firms to use GenAI, and 14% have gone as far as to mandate it in RFPs. That’s almost double the proportion doing the same for law firms.

Beastrom is clear on what that means, saying that clients have emerged as “one of the most powerful catalysts” for GenAI adoption in firms, adding that they’re “increasingly expecting the efficiency gains and innovative approaches that GenAI enables, making adoption not just a nice-to-have but a business imperative”.

This shift marks a new power dynamic. In the past, clients hired firms based on credentials and reputation. Now, they want proof of innovation – and AI capability is fast becoming a prerequisite. Firms that fail to show progress risk losing business before a pitch even begins.

GenAI’s entry point into accountancy may have been in automating routine tasks, but its trajectory is unmistakably upward – from paperwork to partnership.

At EY, the message from clients is equally blunt. “Increasingly, clients are expecting AI capabilities but are looking for it to go beyond automation,” says Joe Depa, EY’s global chief innovation officer. “They want to know: how does AI help me make better decisions, manage risks, and move faster than my competition?” 

The message is consistent across the industry: GenAI isn’t just transforming how firms work. It’s reshaping what clients expect, and how quickly they’ll move on if they don’t see it.

GenAI’s entry point into accountancy may have been in automating routine tasks, but its trajectory is unmistakably upward – from paperwork to partnership.

Thomson Reuters’ data shows the top use cases are now tax research (77%), return preparation (63%), and advisory services (62%). That last figure is telling. GenAI is no longer just helping professionals file faster; it’s changing how firms deliver insight and shape strategy.

“In tax advisory services, which is already among the top use cases at 62% adoption, GenAI is transforming how professionals analyse complex regulatory environments and develop sophisticated planning strategies,” Beastrom says. “It’s enabling a fundamental shift in client service models, allowing for more responsive, customised interactions that strengthen relationships.”

Even audit – long seen as a rigid, rules-based function – is being redefined.

At EY, that shift is already in full motion. Depa highlights the launch of EY.ai Agentic Platform, which integrates AI agents into high-stakes client work, saying, “This deployment will enable AI agents to respond to real-time events, adapt to regulatory changes, and drive smarter financial and risk decisions across global operations.”

Even audit – long seen as a rigid, rules-based function – is being redefined. “We’ve embedded next-generation AI into our Global Assurance Technology Platform, enabling real-time anomaly detection, continuous audit cycles, and proactive issue spotting,” Depa says.

In practice, this means GenAI is being applied not just to do work faster, but to ask better questions, anticipate problems, and personalise advice. It’s a shift from execution to foresight – and the firms investing in it aren’t just streamlining operations; they’re rewriting their value proposition.

For all the enthusiasm and urgency around GenAI, the back-office picture is murkier. As adoption accelerates, most firms are still running without a map. According to Thomson Reuters, 70% of tax and accounting firms currently have no formal policies governing GenAI use. It’s a striking figure and a growing liability.

“Without proper governance frameworks, firms run the risk of creating an environment where professionals may inadvertently misuse the technology,” warns Beastrom. “Firms should begin addressing this gap by conducting a thorough risk assessment to identify specific vulnerabilities in their informal usage patterns.”

Both EY and Thomson Reuters stress that training, transparency and internal guardrails are no longer optional – they’re prerequisites for scaling AI responsibly.

Even the firms furthest ahead are still navigating the steep learning curve. Depa points to a dual challenge at the Big Four firm: internal confidence and client trust. “While most people (82%) are currently using AI as part of their work and careers, not all of them are comfortable with it – only 57%,” he says. “At EY, we have committed to upskilling and training our workforce, to provide them with the tools they need to succeed.”

Both EY and Thomson Reuters stress that training, transparency and internal guardrails are no longer optional – they’re prerequisites for scaling AI responsibly.

“Being transparent with clients about how and when GenAI is used in their work is also crucial,” adds Beastrom. “Implementing clear guidelines on appropriate use cases and establishing quality control mechanisms are essential steps.”

Without this foundation, the risk isn’t just reputational, it’s operational. The tools are evolving faster than the rules, and the firms that don’t catch up may find themselves exposed.

By 2027, nearly 80% of tax and accounting firms expect to have significantly integrated GenAI into their operations. But adoption alone won’t define success. Beastrom believes that the most successful firms won’t just deploy isolated AI tools but will “achieve deep integration across their entire service delivery model”.

Firms that remain cautious or fragmented in their approach may struggle to keep up as GenAI moves from novel to necessary.

Strategic implementation is just the beginning. The differentiators, she said, will span talent, transparency, and cultural adaptation. “They’ll excel at talent transformation – helping professionals evolve their skills to focus on the higher-value activities that complement AI capabilities,” she explains. “Cultural adaptation is also key – firms that foster organisational cultures that embrace technological change rather than resisting it will be the leaders that will reap the benefits of AI.”

Depa echoes the shift from experimentation to expectation, both from clients and from leadership. “AI is elevating expectations for leadership at every level,” he says. “For partners, the shift has been much more consultative – guiding clients not just on what AI can do, but how to integrate it responsibly and strategically.”

Firms that remain cautious or fragmented in their approach may struggle to keep up as GenAI moves from novel to necessary. Those that move now – investing in infrastructure, policy, and talent – stand to not only lead the market.

The accounting profession is crossing a technological threshold, from which there is no turning back. What was once a cautious curiosity about GenAI has become a strategic imperative. Clients are demanding more. Talent is evolving. And the firms that lead will be those that not only adopt AI, but reimagine how they operate with it at the core.

As Beastrom put it, the data presents both “tremendous opportunities and important challenges” for the tax profession. The next two years will determine who rises to meet them – and who gets left behind.