A number of banks say they are aware that many customers are yet to have their salaries transferred into their accounts this morning.
It follows reports from a number of public sector workers that they have not been paid into their bank accounts.
The Department of Justice, which is responsible for the central unit that pays most public workers, has said it is working with banks to determine the problem.
Permanent TSB, AIB, Ulster Bank and Bank of Ireland have all said they are looking into the issue.
Bank of Ireland also issued a statement his morning saying, "We have reports of some payments being delayed which we are investigating urgently.
"Our focus is always to ensure prompt payment for our customers. We will issue a further update shortly."
Ulster Bank said that after investigations, they had found no problems at their end and that all their payments had been processed.
However, the bank also said any of its customers experiencing payment issues can take out up to €500 at the counter if they present their payslip and a valid ID.
It is believed the delay is similar to an issue that occurred last month, when a delay at Bank of Ireland led to delays in wages for tens of thousands of workers.
The Irish Times' consumer affairs editor Conor Pope says problems with one bank can quickly spread to others.
"The banking system is so intermeshed that (even though) they're all different banks, they all depend on each other," he said.