Multinational companies are going to be subject of new tax rules as part of reforms to be announced today by the OECD.
International companies with revenues of more than €750m will have to report their activities in each country they operate in.
The new rules are the result of a two-year project from the OECD aimed at improving transparency.
Peter Reilly of PriceWaterhouseCooper says the new rules will have interesting consequences.
He said: "The proposals on transparency will be very interesting and I think the OECD will trumpet them as being a huge success.
They will effectively allow tax authorities to see what multinational companies are doing in all jurisdictions, and not just their own.
"So that will give an awful lot of food for thought for large companies who are doing business in a number of juriscdictions. On balance the proposals should offer good opportunities for Ireland."