Margreet Logmans wrote:
As far as I know, these sort of rules do not apply internationally. In Italy, to Italian clients, they may apply, but not to German clients in German. You can't expect the German economy to contribute to the Italian social security system. Also, 'to be given the opportunity' is not the same as 'must'. I can't imagine it is obligatory for you to charge these.
Anyway, I advise you to raise your rates by 4% for all work you do for people outside Italy. That should save you a lot of trouble.
My two cents!
And it should not be applied internationally, just in Italy to Italian clients