A Citigroup office is seen at Canary Wharf in London, Britain May 19, 2015.
Reuters/Suzanne Plunkett
Citigroup Inc said on Friday it resolved a technical issue that had left customers unable to access their accounts remotely.
Customers had taken to social media to complain about the major outage.
"We experienced a brief technical issue that is now resolved," Citigroup's customer service Twitter account said in response.
Bloomberg reported the news of the outage first.
A Bloomberg reporter spoke with four people at a bank branch on Manhattan's Upper East Side who said debit cards did not work at the ATM there. (bloom.bg/296tSVr)
Citigroup was not immediately available for further comment.
(Reporting by Anya George Tharakan in Bengaluru; Editing by Sandra Maler)