Nationwide has been fined £44m by the City watchdog over “weak” financial crime controls that culminated in a serious case of Covid fraud that left UK taxpayers £800,000 out of pocket.

The Financial Conduct Authority (FCA) fined the building society for failures stretching over nearly five years. It said the lender had been aware that some customers were using personal accounts for business activity, in a breach of its own terms.

Nationwide did not offer business accounts at this point and so did not have the right processes in place to monitor potential financial crime risks, the FCA said.

The practice resulted in a case where Nationwide failed to catch a customer using personal current accounts to receive 24 fraudulent Covid furlough payments, totalling £27.3m over 13 months. About £26m of that sum was deposited in only eight days.

While HM Revenue and Customs has managed to claw back £26.5m from the fraudsters, approximately £800,000 remains unrecovered, leaving taxpayers out of pocket over Nationwide’s failures.

Therese Chambers, a joint executive director of enforcement and market oversight at the FCA, said: “Nationwide failed to get a proper grip of the financial crime risks lurking within its customer base. It took too long to address its flawed systems and weak controls, meaning red flags were missed with serious consequences.

“Building societies and banks have a key role in the fight against financial crime. Firms must remain vigilant in this fight.”

The failures related to October 2016 to July 2021, and while Nationwide tried to make improvements, the FCA said it “failed to adequately address those weaknesses in a timely manner”. It was later forced to undertake a large-scale financial crime transformation programme in July 2021.

“We are sorry that our controls during the period fell below the high standards we expect,” Nationwide said in a statement.

A spokesperson for Nationwide building society said it had identified the issues through its own reviews, voluntarily brought it to the attention to the FCA and “cooperated fully” with the regulator’s investigation.

“Since 2021, Nationwide has invested significantly in all aspects of its economic crime control framework in order to ensure our systems are robust,” they added.

“We do not believe that these controls issues caused financial loss to any of our customers and remain committed to preventing economic crime and protecting our customers and the wider UK economy from fraud.”