ULSTER Bank has been hit by yet another IT glitch, with its mobile banking system locking customers out.
It is the latest in a string of computer-related problems suffered by customers.
The problem affected account holders with Ulster Bank, NatWest and Royal Bank of Scotland.
Users of mobile applications for iPads, iPhones, BlackBerry devices and android phones found they were unable to get access to their banking services on their mobiles. Technicians spent hours working to restore the service for users in Ireland and the UK.
A spokeswoman for Ulster Bank said the mobile banking service was out of action for several hours yesterday, but she insisted that online banking accessed from computers had continued to work.
"The problem has now been fully resolved for Ulster Bank customers and our mobile banking applications are now up and running as normal," she said.
"No other systems were impacted, and we apologise to customers for any inconvenience caused during this short disruption to service."
This is the latest in a string of embarrassing service collapses experienced at the British-owned bank.
Earlier this month, it apologised to customers who had been reporting problems using bank cards and making electronic transactions.
Last summer, computer faults paralysed all payment services for 600,000 Ulster Bank customers for several weeks.
The bank was forced to offer to refund and pay any charges or loss of interest to customers.
Workers were unable to access their wages unless they went into a bank outlet after a software upgrade went wrong.
Both the Central Bank here and the Financial Services Authority in Britain are conducting investigations into last year's IT problems.
These are expected to look at splitting the IT system, as Ulster, RBS and Nat West currently operate off the same shared platform.
Ulster Bank has been making headlines for all the wrong reasons lately.
Last month it emerged that 1,300 mortgage customers had been under-charged for their home loans for years.
The bank said in January that it plans to close around 20 branches, 10 on each side of the Border.
Its parent, Royal Bank of Scotland, has pumped at least €12bn into its unprofitable Irish unit since 2008 to absorb losses incurred with the collapse of the economy here.
In November, Ulster Bank was fined €2m by the Central Bank for failing to keep enough money in reserve to comply with regulations.