From here: https://en.wikipedia.org/wiki/Double_Irish_arrangement#Controversial_closure_(2015) https://en.wikipedia.org/wiki/Double_Irish_arrangement#Contr...

From here: https://en.wikipedia.org/wiki/Double_Irish_arrangement#Controversial_closure_(2015) https://en.wikipedia.org/wiki/Double_Irish_arrangement#Contr... The 2014–16 EU investigation into Apple in Ireland (see below), showed that the Double Irish existed as far back as 1991. Early U.S. academic research in 1994 into U.S. multinational use of tax havens identified profit shifting accounting techniques.[7][36] U.S. congressional investigations into the tax practices of U.S. multinationals were aware of such BEPS tools for many years.[37] However, the U.S. did not try to force the closure of the Double Irish BEPS tool, instead it was the EU which forced Ireland to close the Double Irish to new schemes in October 2014.[38] Nevertheless, existing users of the Double Irish BEPS tool (e.g. Apple, Google, Facebook, Microsoft, amongst many others), were given five more years until January 2020, before the tool would be fully shut-down to all users.[29][39] tl;dr It was the EU that shut down the Double Irish. The US gave them until 2020, so they milked it as long as they could.