The HSBC banking network suffered an outage in the UK on Friday caused by problems with one of the company's mainframe computers.
The bank's network of ATMs went down at around 11.45am, and was back up and running by 3.30pm, an HSBC spokesperson told ZDNet UK on Friday.
In addition to bank machines, HSBC's point-of-sale card network was down, while internet banking also suffered intermittent outages.
"We'd like to apologise to all of our customers, and we are looking at the reason for the outage," said the bank's spokesperson. "The outage was linked to the mainframe, but in terms of specific issues, we are still looking into that."
The banking giant is in the process of upgrading its IT systems, under the 'One HSBC' rubric. The spokesperson said that while the cause of the outage was unknown, the upgrade was unlikely to have been behind it, due to the maturity of the One HSBC plans.