Ulster Bank customers should be able to access a full range of services from next week, according to the lender's parent company Royal Bank of Scotland.
Technical problems have caused payments into and out of Ulster Bank accounts to be disrupted since last week. The problems are affecting some 100,000 customers in Ireland. In Britain, RBS and Natwest customers have also been affected by the issue.
In a statement tonight, RBS cancelled its corporate hospitality at Wimbledon in the wake of the IT meltdown.
"Under the circumstances, we felt it would be inappropriate to provide client hospitality at Wimbledon. Our people are focused on resuming normal service for our customers as soon as possible," it said.
The bank had already hosted clients for the first two days of the championships and had planned to do so for the rest of the fortnight.
The bank declined to divulge how much money it had planned to spend on hospitality.
In a statement this afternoon, Jim Ryan, managing director of branch banking with Ulster Bank, said the bank was "working around the clock" to clear the backlog and said that he was confident full service would be restored for the start of next week.
"In the meantime, customers continue to experience unacceptable delays to their accounts being updated. We remain grateful to them for their patience and we apologise unreservedly for the continued inconvenience. We can confirm that no customer, including customers of other banks, will be out of pocket as a result of this issue," he said.
He said 80 branches would extend their opening hours until 7pm daily for those who cannot make it during working hours. Anyone unable to visit a branch should call 1800 205100 where they will be assisted, he added.
Customers who have experienced delays in receiving their salaries or social welfare benefits can withdraw money on the production of payslips and identification. Cash can also be taken out on credit cards, interest free. The ATM network is working as normal.
Mr Ryan said 33,000 people visited various branches of the bank around the country yesterday and 20,000 calls were handled at the bank's call centre.
RBS said earlier today the update of customer balances following a computer glitch "has cleared overnight, with the exception of a few specific sets of transactions".
"It is possible a small number of customers may experience delays as we return to a completely normal service," it said.
While customers affected to date have mainly been those paid weekly or making once-off transactions, monthly salaries are due to be paid this week.
Customers should check the bank's website, ulsterbank.ie, for branches that are open and for relevant telephone numbers.
In a statement yesterday, the Central Bank said it had been in contact with Ulster Bank to "press the bank to resolve the situation as quickly as possible and ensure that customers are treated fairly".
"At a meeting with Ulster Bank senior management today, the Central Bank emphasised the importance of clear communication and support to consumers," the statement added.