Citigroup (NYSE:C) erroneously credited a client's account with $81T in what should have been a $280 transaction, a mistake that could extend regulators' scrutiny as the bank attempts to convince them that it has fixed operational issues,

Citigroup erroneously credited $81 trillion, instead of $280, to a customer's account and took hours to reverse the transaction, a "near miss" that shows up the bank's operational issues it has sought to fix,

Citigroup reported the "near miss" to the Federal Reserve and the Office of the Comptroller of the Currency, according to the Financial Times.

Citigroup credited $81 trillion to a customer’s account, instead of just $280, and took hours to reverse the transaction — an embarrassing “near miss” for a bank that has struggled to fix operational issues.