Services were affected on Sunday afternoon with the glitch fixed by around 19.30, according to a tweet sent out by the HSBC UK press account.

The bank apologised to angry customers, many of whom had taken to Twitter themselves to berate it and threaten to move accounts:

@hsbc_uk_press I'm a (soon to be ex) business customer. I'm losing thousands of pound in online transactions. Where do I get info?

— Andrew Collier (@andrewcollier) May 20, 2012

However, others were more forgiving and appreciative of HSBC's Twitter updates:

@hsbc_uk_press :) I know you'll have copped a lot of flak today, but cheers for the update. Payments going through now for me.

— Jane Copland (@jane_copland) May 20, 2012

The bank has developed a dedicated social media monitoring team in recent months, prompted by a major IT outage in November. Speaking at Finextra's Social Media Day in April, the man behind the platform, Neil Kirkman, revealed that he had secured its budget following the disaster, which demonstrated the huge reputational risk of not taking a proactive approach to monitoring and interacting with customers online.