Japan's financial services regulator has ordered Citibank to improve its computer systems following a technical glitch that caused more than a quarter of a million incorrect transactions.
The botch-up occured at the bank's Japanese unit and was caused by an incorrect batch process that occured following the implementation of a new system.
The systems failure resulted in the bank failing to properly credit customers for withdrawals and deposits made between 2 May and 8 May, a period that included a series of public holidays.
The glitch resulted in around 275,000 incorrect transactions. About 200,000 of the transactions were processed but did not appear in statements. The rest of the transactions were recorded in accounts twice by the faulty system.
According to press reports Japan's Financial Services Agency (FSA) has now ordered the bank to improve risk management, internal controls and systems development procedures.
The FSA has ordered Citibank to submit a business improvement plan by 14 August and then, starting in December the bank has to file reports every three months detailing steps taken to improve its operations.