Businesses hit by losses linked to AI tax guidance, survey finds

UK businesses are losing money after relying on general-purpose artificial intelligence tools such as ChatGPT for tax, bookkeeping and financial advice, according to research conducted by Dext.

The survey of 500 accounting professionals across the UK found that 50% were aware of businesses suffering direct financial losses after acting on incorrect or misleading AI-generated guidance. Those losses included overpayments, missed allowances, penalties, fines and wider compliance issues.

The research suggests that the rapid adoption of public AI tools by businesses is creating new financial and regulatory risks, particularly where automated outputs are treated as a substitute for professional advice.

More than three quarters of accountants and bookkeepers said they had seen an increase during 2025 in clients using public AI tools to seek financial, tax or bookkeeping advice. At the same time, 72% reported a rise in clients using AI-generated outputs to question or challenge professional advice, while 68% said more clients had suggested AI could replace the need for professional accounting services.

That growing reliance is being accompanied by a rise in errors. Nearly a third of respondents said they now encounter client mistakes caused by incorrect AI-generated advice on a weekly basis, while 7% said they see such errors daily. A further 28% said they encounter them monthly.

The most common problems reported included incorrect interpretation of business expenses, wrongly claiming or charging value added tax, flawed personal tax planning, payroll errors and incorrect business tax planning advice.

Beyond direct financial losses, accountants said correcting AI-related mistakes is creating a growing drain on time and productivity. Among those who encounter such errors, 93% said they spend up to ten hours a month fixing problems linked to AI-generated advice. Almost four in 10 said they spend between four and 10 hours a month on this work.

Looking ahead to 2026, accountants warned the risks could intensify if businesses continue to rely on public AI tools without professional oversight. A third of respondents said this could increase the risk of insolvency or business failure. Others pointed to a higher likelihood of fines and penalties, increased scrutiny from HM Revenue and Customs, and the misuse of AI outputs to justify inappropriate or fraudulent claims.

Nearly half said they expect more businesses to make decisions based on misplaced confidence in inaccurate AI-generated advice, compounding financial and compliance risks.

The findings have prompted widespread calls for intervention. More than nine in 10 accountants and bookkeepers surveyed said public AI tools should be regulated or restricted when providing tax or financial guidance, with 70% calling specifically for formal regulation.

Paul Lodder, vice-president of accounting product strategy at Dext, said: “The damage is no longer hypothetical,” he said. “Businesses are already losing money, and accountants are spending valuable time correcting avoidable mistakes, from VAT and payroll errors to misinterpretation of expenses.

“AI has a powerful role to play in finance, but there is a fundamental difference between specialist tools built for accounting and bookkeeping, and general-purpose chatbots that do not know a business’s true financial context.”