Despite buoyant market reaction to the millennium bug's limited impact, there are concerns that the State's 7,500 small firms may encounter problems as business resumes this morning.
A survey conducted in October by Enterprise Ireland and the Small Firms Association found 40 per cent of companies had no Y2K contingency plans should something go wrong.
Of those which had taken measures to avoid the bug, many found their efforts were necessary, although 90 per cent believed the problem had been "over-hyped".
Mr Pat Delaney, association director, said the biggest concerns were possible breakdowns in compliant firms' supply streams should suppliers break down.
In general, the extent of any failures are considered likely to be local. Y2K expert, Mr Patrick O'Beirne of Systems Modelling, says: "There will be inconveniences, but hopefully they will only affect those that deserve it. The major question is whether the glitches will be bad enough to affect customer service. Most likely it will be possible to rectify them manually, which means more work, but it can be done."
The systems thought most likely to be affected are billing and accounting systems which are date dependent. Companies are advised to also check balances on customer accounts, and compare them with end-of-year figures.
The general manager of Irish Small and Medium Enterprises, Mr Ciaran McMahon, had received no reports of any problems and the group's Y2K hotline had had no calls.
Mr McMahon said that "by and large", small and medium firms would have addressed the problem from early last year.
Separately, the global Y2K alert yielded some benefit at least when the Internet address www. year2000.com sold to the highest bidder for $10 million (€9.7 million) on Saturday.
The sale, which took place on online auction site e-Bay, will be the biggest payment yet for an Internet domain name. The identity of the successful bidder has not been disclosed.
The website was owned by Canadian computer consultant Mr Peter de Jager, who was among the first to initiate the Y2K alert.