Published Tuesday, 03 December 2013
The technology meltdown left customers of the Royal Bank of Scotland (RBS) Group, which includes NatWest and Ulster Bank, without the use of their debit or credit cards.
It also affected the banks' online services and smartphone apps.
Reports of problems began from around 6.30pm on 'Cyber Monday', which is traditionally the busiest day of the year for online shopping.
On Tuesday morning, Ulster Bank issued a statement to confirm normal service has resumed and the systems issues have been resolved.
I'm sorry for the inconvenience we caused our customers. We know we have to do better.
Ross McEwan, Ulster Bank
A spokesperson said anyone who has any further issues should contact Ulster Bank via their helpline or call into a branch.
A major technical glitch in June last year left Ulster Bank customers without proper access to their bank accounts for weeks - the bank ended up paying out £18m to almost 300,000 people in compensation.
A hardware problem also meant customers were unable to access their accounts, make online transactions or use their bank cards for several hours in March.
Ulster Bank said the technical issue was not the same as last year's glitch.
Ross McEwan from the company added: "Last night's systems failure was unacceptable. Yesterday was a busy shopping day and far too many of our customers were let down, unable to make purchases and withdraw cash.
"For decades, RBS failed to invest properly in its systems. We need to put our customers' needs at the centre of all we do. It will take time, but we are investing heavily in building IT systems our customers can rely on.
"I will be outlining plans in the New Year for making RBS the bank that our customers and the UK need it to be. This will include an outline of where we intend to invest for the future."
SDLP MLA and chair of the Stormont Enterprise committee, Patsy McGlone has called for an urgent meeting with Ulster Bank.
"The considerable inconvenience caused to people and, indeed embarrassment, to those out shopping and having meals cannot be compensated," the Mid Ulster MLA said.
"Last July, the bank assured the Enterprise Committee a detailed investigation would be carried out into the issue which went on for weeks, but we're still trying to get to the bottom of it and waiting on a report from the Financial Conduct Agency.
"If they have produced a report we haven't seen. Ulster Bank has serious questions to answer."
Also reacting was former Finance Minister and DUP MP Sammy Wilson, who said the latest problem has left customers "fearful" following further inconvenience.
"The bank must learn from the mistakes of the last time and be honest about the extent of the problem and put the resources into fixing it," he said.
© UTV News