Tara Burke, a company spokeswoman, said the outages were the result of system upgrades over the weekend. She declined to say whether the company had anticipated that the upgrades would result in outages. But she said that no customer information was compromised and that the problems were not the result of hacking.
"We hope to have it restored as quickly as possible," Burke said.
Bank of America's online banking service also experienced outages for almost an entire day in January.