Directors are facing fines of up to €5,000 from the Companies Office if they fail to collate and register information on the beneficial owners of their company before a September.
The new obligations are imposed by the EU anti money laundering directive.
"There's a current obligation on all Irish registered companies - save for those listed in the jurisdiction - to identify who their beneficial owners are, by which I mean the individuals who ultimately own the company either directly or indirectly," said to Nick Metcalfe, who is a senior associate with Mason Hayes and Curran.
He said that companies are currently required to keep such details on an internal register - but the change set to be brought in by the upcoming legislation will require that data is also passed on to a central register.
The deadline for compliance is expected to be in quarter four, but the matter is somewhat complicated by the fact that the legislation giving effect to this in Irish law has not yet been finalised.
"We don't know exactly what the legislation is going to look like and when the filing deadline is going to be," he said. "We also don't know quite yet the level of access that will be granted to the information once it is collated on the central registry."
Mr Metcalfe also said that companies are expecting a three-month window to be offered to allow them to make a filing without penalty - however they will have to wait for the legislation to see if that materialises.
But for some the task of simply finding the correct beneficial owners may be a challenge in itself.
"The majority of companies will be either owned by their directors or by persons known to the directors," said Mr Metcalfe. "But where the company in question is a subsidiary within a much larger group, and the ultimately ownership is maybe five or six steps removed, it isn't necessarily known to the directors as a matter of course who those beneficial owners are."
He advises such firms to raise inquiries with their central administration as soon as possible so they can find out the details in time for any legislative change.
The changes being brought in are part of efforts to tackle money laundering across Europe and the wider world - though Mr Metcalfe points out that it is only really one degree removed from the existing requirements to list a company's shareholders.
The real question for companies, he says, is how public the information will be once it's centralised - and who will have access to each company's list of beneficial owners.