[sbacic]

> The company would pay corporation tax in Ireland.

You'd assume that, but you could also very well be wrong. Depending on tax treaties and the "effective place of management" principle, he could be liable for corporation tax in Spain or in both Spain and Ireland.

One reason why tax laws get very complicated very fast is because every country wants to tax everything it can which inevitably means that two different countries end up taxing the same thing. To avoid this, you get double taxation treaties and loopholes.