UK businesses losing money to ChatGPT-style tax and financial advice, accountants warn

London, 18 December 2025: British businesses are losing money after relying on general-purpose AI tools such as ChatGPT for financial, bookkeeping and tax advice, with accountants and bookkeepers warning the risks could escalate into business failures by 2026.

That is according to new research of 500 accountants and bookkeepers across the UK by Dext, which found that 50% are aware of businesses that have suffered direct financial losses - including overpayments, missed allowances, penalties, fines or compliance issues - as a result of incorrect or misleading AI-generated advice.

The findings suggest AI adoption is accelerating across British businesses, but that misuse of public AI tools for complex financial decisions is creating a growing and costly risk, one the nation’s business guardians fear will intensify as more firms treat AI outputs as reliable guidance.

“The damage is no longer hypothetical,” said Paul Lodder, VP accounting product strategy at Dext. “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’s a fundamental difference between specialist tools built for accounting and bookkeeping, and general-purpose chatbots that don’t know a business’s true financial context.”

AI reliance surges as clients challenge professional advice

Throughout 2025, 77% of accountants and bookkeepers say they have seen an increase in clients using public AI tools, such as ChatGPT or other large language models, to seek financial, tax or bookkeeping advice.

At the same time, 72% have seen an increase in clients using AI-generated outputs to question or challenge professional advice, while 68% report a rise in clients suggesting that AI could replace the need for professional accounting services.

However, this growing reliance is being accompanied by a sharp rise in errors, with consequences already showing up in client finances.

‘AI slop’ in the books

Nearly a third (31%) of accountants and bookkeepers say they now encounter client mistakes caused by wrong or misleading AI-generated financial or tax advice on a weekly basis, with an incredible 7% seeing such errors daily. A further 28% come across these monthly while only 5% say they have never encountered public AI-driven mistakes.

The most common errors reported include incorrect interpretation of business expenses (46%), incorrectly claiming or charging VAT (41%), flawed personal tax planning (35%), payroll errors (34%) and incorrect business tax planning advice (34%).

The hidden cost: hours wasted fixing AI mistakes

Beyond direct financial losses, the research highlights a growing productivity drain on the accounting and bookkeeping professions, and unnecessary hours billed to businesses.

Among those encountering public AI-related mistakes, 93% estimate they spend up to ten hours each month correcting errors caused by AI-generated advice, including 44% who spend up to three hours per month, and 39% spending between four and ten hours.

2026 warning: insolvency risk, fraud, penalties and HMRC scrutiny

Looking ahead to 2026, accountants expect the risks to intensify if businesses continue relying on public AI tools without professional oversight.

A third (33%) warn of a higher risk of insolvency or business failure, while others expect increased misuse of AI outputs to justify inappropriate or fraudulent claims (43%), rising fines and penalties (38%), and greater HMRC scrutiny due to incorrect or late filings (37%). Nearly half (45%) believe businesses making decisions based on false confidence in incorrect AI outputs will become more common.

Calls for regulatory clamp down 

With concerns mounting, accountants are calling for urgent intervention. More than nine in ten (92%) believe public AI tools should be regulated and/or restricted when providing financial or tax-related advice, with 70% specifically calling for formal regulation.

Lodder added: “If we head into 2026 with more businesses treating AI outputs as trusted tax and financial advice, without professional oversight, the consequences could be severe. The focus now should be on responsible guardrails, clearer restrictions around financial advice, and better education for businesses on what these tools can and cannot safely be used for.”

ENDS

NOTES TO EDITORS

About the data

The quantitative research was commissioned by Dext and conducted by Censuswide. It surveyed 500 UK accountants and bookkeepers working across a range of firm sizes, regions and industries. Fieldwork took place over the first two weeks of December 2025.

About Dext 

Dext, part of the IRIS Software Group, is the leading provider of AI-powered bookkeeping automation. Founded in 2010, the company empowers businesses, accountants, and bookkeepers to thrive through cutting-edge artificial intelligence and machine learning technology that simplifies accounting processes and enables smarter, more timely financial decisions. 

Trusted by thousands of professionals worldwide, Dext integrates with major accounting software and connects to over 11,500 banks, suppliers, and marketplaces.

In 2024, Dext joined IRIS Software Group and continues to work directly with its clients to create a more seamless, end-to-end accountancy workflow. For more information, visit www.dext.com.