A routine transaction at Citigroup nearly resulted in an $81 trillion error—an amount five times the total wealth of the UK—due to a simple but significant manual mistake. The error, which occurred in April 2024, was detected before any funds left the bank, preventing a potential financial catastrophe.
How the Error Happened
According to an internal account cited by the Financial Times, the mistake occurred when a Citi employee attempted to send just $280 (€269) to a client’s account. Due to a system malfunction, the employee had to use a rarely accessed backup screen to process the payment.
However, the backup system’s payment field was pre-filled with 15 zeros, which should have been manually removed. Instead, the transfer was initiated with the incorrect value, leading to a near miss of $81 trillion (€77.8tn).
The mistake was initially overlooked by two employees, including one responsible for verifying transactions, before being flagged by Citi’s internal controls the following day.
No Funds Left the Bank
Despite the magnitude of the error, Citi confirmed that no money actually left the bank, which itself is worth significantly less than the transfer amount—the bank’s market capitalization stands at approximately $150 billion (€144bn).
The financial institution promptly reported the incident to US regulators, including the Federal Reserve and the Office of the Comptroller of the Currency.
Citi referred to the error as a “near miss”, a term used to describe incidents where incorrect transactions are caught before completion. The bank assured that its detection systems functioned as intended, stating:
“Our detective controls promptly identified the inputting error between two Citi ledger accounts and we reversed the entry. While there was no impact to the bank or our client, the episode underscores our continued efforts to eliminate manual processes and automate controls.”
A Pattern of Costly Errors
Although this specific blunder was rectified in time, it highlights Citi’s ongoing struggle with operational mishaps. The bank has reported at least 10 transaction errors exceeding $1 billion in 2024 alone, with 13 similar cases the previous year, according to internal documents reviewed by the Financial Times.
This comes nearly five years after Citi mistakenly sent $900 million to cosmetics firm Revlon in 2020—a high-profile error that led to a legal dispute and the departure of former CEO Michael Corbat.
As Citigroup continues to work on fixing its internal controls, the incident underscores the risks of manual banking processes and the increasing need for automation in high-value financial transactions.