Wise Group is negotiating a settlement with the U.K. taxes collection agency after third-party software failures caused some customers to make incorrect payments over a four-year period.

The fintech company contacted some users of its interest and stocks investment products, as it had provided incorrect tax statements between 2021 and 2025.

Wise is negotiating with HM Revenue & Customs to correct the payments at its own expense, and self-reported the issue after an investigation.

The issue stemmed from a software failure from a third-party provider, which was identified through Wise's internal quality controls. News of the error was reported by the Financial Times on Thursday.

"Wise identified that errors in software used by a third-party provider led to incorrect tax statements for a limited number of customers using our Wise Interest and Stocks investment products," the company said.

"We have fixed the issue, issued corrected statements to affected customers and are proactively redressing potential liabilities, with no ongoing risk to customers."

The error is the latest challenge for the company, after Belgian authorities launched a money-laundering probe in June over suspicious transactions worth over 500 million euros ($559.9 million).

At the time, a spokesperson for the Brussels prosecutor's office said it was close to issuing Wise with "a direct summons before the criminal court."

Wise said in June that it was working to respond to the prosecutor's queries about its business. It added that inquiries were still incomplete and no specific findings had been shared with the company.

In July, Wise's application for a U.S. national trust bank charter was denied by the Office of the Comptroller of the Currency, a primary U.S. banking regulator.

The regulator cited deficiencies in its program to combat money laundering and terrorism financing.

The OCC decision came after Wise moved its primary stock market listing to New York last year, while retaining a secondary listing on the London Stock Exchange. At the time, the company said it saw in the U.S. the biggest market opportunity in the world for its products.