Tax residence and international taxation

Those who receive income originated in different states, subject to taxation regimes, often do not know where they have to pay taxes.
It is advisable, in order to avoid very severe penalties, to establish with certainty the tax residence and prove the correctness of the choice.
It is not always easy to identify the main seat of the affairs, a prerequisite for figuring out what the appropriate tax residence is.
To make the correct choice, Italian, foreign and international source regulations have to be taken into account.