BANK customers may have their salary payments and social welfare claims delayed due to technical problems.
Ulster Bank was hit by a technical glitch that saw automated payments failing to appear in customer accounts.
The financial institution said that the some transfers could be delayed by the problem -- but they expect that the system will be back up and running by tomorrow.
The company was "aware of a technical issue affecting a number of Ulster Bank systems".
Up to 6,000 social welfare customers were affected by the bank's technical glitch, a Department of Social Protection spokesman said.
It is understood that customers whose delayed wage payments affected their mortgage payments would not be penalised by the bank.
"We apologise to our customers for any inconvenience this may cause," the bank said in a statement.
Ulster Bank is the third-largest retail bank in Ireland and has about 1.9 million personal and business customers on the island.
There are more than 120 branches across the State and more than half a million of its customers are registered for its Anytime Banking online service.
Further information will be available on its website throughout the day.