I have been working and living in several EU countries over the past years and a few things surprise me..
The Italian case mentioned above makes no sense at all. Not saying that it is incorrect, just not in line with EU tax policies.. Your citizenship has normally NOTHING to do with your tax liability in the EU.
What matters is 1. Where is the main business of you company registered. 2. Where is your main place of abode. 3. Any tax regulations signed specifically between country 1 and 2 that overrules EU tax agreements.
You are tax liable in country 1 (above) and may, or may not, be taxed by that country. You are also tax liable in country 2 (above) but country 2 cannot tax you on income that you have already paid tax for in country 1, this is where dual tax agreements step in to protect you from double taxation. What you may end up having to do is pay in some tax to country 2 if the tax in this country is HIGHER then what you have in country 1.
Makes sense?
This was the case for me years ago when I lived in Sweden and worked for a company based in another EU country. Just watch out for the Social security fees normally paid for by the employer in Sweden.....you as an employee is responsible for making sure someone (read you!!) is paying these to the Swedish government.. This was the case with the rules signed between Sweden and the country I used to work in. In this case its better to stop working...
Good luck!
/CP