No money left the bank, but the "inputting error" comes as CEO Jane Fraser seeks to convince regulators she is fixing the bank's controls.

The bank temporarily credited a customer’s account with trillions of dollars, adding to scrutiny of risk management systems after a series of errors.

Citigroup narrowly avoided what could have been one of the largest banking blunders in history after it mistakenly credited a client’s account with $81 trillion instead of the intended $280. The Financial Times reported that the error was detected only after two employees overlooked it,