Bank of Ireland customers are experiencing problems withdrawing cash because the bank's computer system has crashed.
The system for all online and telephone banking is down, while some Bank of Ireland customers are also having difficulty withdrawing cash from ATMs.
A spokesperson for the bank has said ATMs are not dispensing different amounts than those requested.
However, some cardholders may be getting money from ATMs even if they do not those funds in their accounts.
The bank's spokesperson said this is because 'in a crisis situation, each individual card holder has an offline line'.
Those customers withdrawing more than they have in their accounts will incur normal charges.
A spokesperson said it is an 'unforeseen temporary technical issue', which the bank is working to resolve.
Tellers could not access the up-to-date balance on customers' accounts during the day.