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.

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,

Citigroup Inc. erroneously credited $81 trillion to a customer’s account instead of $280 last April before reversing the transaction hours later, according to the Financial Times. The bank called it a "near miss.