Bank customers have been told that ATM services will not deteriorate further as a result of the strike at Brinks Allied, which began yesterday.
Workers at the cash delivery company, who have been off the road for more than three weeks in a dispute over new work practices, yesterday placed pickets at the Brinks headquarters in Clonshaugh, Dublin.
They decided to go ahead with an official strike after the company rejected a Labour Court recommendation aimed at resolving the dispute.
The row has disrupted cash supplies to ATMs in Dublin and other parts of the east since the end of July.
There have been fears that an official strike would worsen the situation given that supervisors, who have been carrying out some deliveries, would not pass strikers' pickets.
A number of banks said yesterday, however, that the strike would not cause a further reduction in services.
A spokeswoman for Bank of Ireland said it had 495 ATMs in the affected areas, 68 of which were serviced by Brinks Allied.
These had been shut since the beginning of the dispute and would remain out of operation. All 68 were at "off-site", or non-branch locations, she said.
ATMs at branches and in retail outlets would continue to operate as normal.
Customers had reacted to the dispute by making fewer cash withdrawals, but taking out slightly larger amounts than normal, the spokeswoman added.
There had also been increased use of electronic banking and laser card cashback facilities in shops. AIB and Ulster Bank also said the vast majority of their ATMs remained operational, with only some off-site machines affected by the dispute.
There appeared to be no moves on the cards yesterday to try to resolve the dispute.
Brinks Allied said it was investing more than €2 million in new work practices designed to improve the safety of staff, customers and the public.
It said it regretted that essential improvements in safety and its commitment to investing in Ireland had been "misconstrued" as part of the dispute.
This was an apparent reference to concerns expressed by SIPTU, which represents those on strike, that the company is seeking to exit its Irish operations.
Workers claim the new work practices the company wants to introduce would leave them more vulnerable to attack during armed robberies.