In 2014, Ireland refused to implement the 2013 EU Accounting Directive, and invoked exemptions on reporting holding company structures until 2022, so that multinationals can register as Irish "unlimited liability companies" (ULCs), which do not have to file public accounts with the Irish CRO. However, as most foreign multinationals in Ireland are major U.S. listed companies (see Table 1), tax academics have been able to estimate their Irish ETR from U.S. filings. In addition, the 2014–2016 EU investigation into Apple, Ireland's largest company, produced detail on Apple's Irish ETR from 2004 to 2014.
