> K customers buy ads to be shown in the UK to UK viewers, from UK staff at Google's UK offices. They pay in UK pound sterling, from UK bank accounts. So far everything is in the UK. It is only at the very end of the process that someone in Google's Ireland office pushes a button to close the sale, thus taking the sale out of the UK (and our tax system) and into Ireland and their tax system.

Except, arguably, the most important thing: the search algorithm and database that brings those UK customers to view those ads in the first place.

In any case, my point isn't that what Google is doing is the right answer. My point is that its quite debatable even from our armchairs how much tax revenue the UK is entitled to from Google's activities in the country. Google is just taking advantage of that complexity.