• Citi sustained an $81 trillion "inputting error" last year, though no money left the bank.
• This followed a series of operational blunders that have drawn regulatory scrutiny.
• In 2020, Citi accidentally transferred $900 million to Revlon creditors.

Citigroup's fat-finger blunders may not be over.

The Wall Street bank accidentally credited a client's account with $81 trillion instead of $280, the Financial Times reported on Friday. This followed the accidental transfer of $900 million in 2020 to Revlon creditors due to human error and outdated technology.

A Citi spokesperson did not confirm the figures involved to Business Insider but described the latest incident as an "inputting error" that highlighted improvements to the bank's operational controls because no money was transferred out of the bank.

"Despite the fact that a payment of this size could not actually have been executed, our detective controls promptly identified the inputting error between two Citi ledger accounts, and we reversed the entry, " the spokesperson said in a statement. "Our preventative controls would have also stopped any funds leaving the bank," the spokesperson said, adding that there was "no impact to the bank or our client."

The mishap came amid Citi CEO Jane Fraser's efforts to convince shareholders and regulators that she's turning the bank around. It points to Citi's struggle to iron out the kinks in its tech and compliance frameworks — the central goal of a sweeping, multiyear plan called the Transformation, which aims to help the bank prove to regulators that its risk controls have improved over the years.

This is the latest in a series of glitches for Citi, which has had to pay US regulators $400 million in fines over its data management and risk controls. In July, shortly after the $81 trillion mistake, Citi was hit with $135.6 million in fines for failing to make enough progress to satisfy the Federal Reserve and Office of the Comptroller of the Currency.

British regulators also fined Citi about $79 million in May for a 2022 incident in which a Citi employee accidentally added a zero to a trade, which caused a flash crash in Europe.

The blunders and fines add to the mounting pressure on Fraser, who inherited the bank's outdated systems and regulatory issues when she took over in March 2021. US Sen. Elizabeth Warren in October urged the OCC to place growth restrictions on Citi, saying the bank had become "too big to manage."

Fraser has dedicated billions of dollars to a firmwide initiative to overhaul the bank's technology. The bank has about 12,000 employees working on its Transformation project, which is overseen by the Citi consumer-bank veteran Anand Selva.

After the July fines, Fraser tapped Tim Ryan, the bank's head of tech, to lead the effort to improve its data controls alongside Selva.

Fraser has defended Citi's progress in earnings calls, reiterating that improving its systems is a yearslong process.

"We know what we need to do," she said on a fourth-quarter earnings call with analysts in January. "We've got our arms around all of this. We're just getting on with execution."