Double taxation treaties are treaties that normally only involve two states and provide specific rules on which state is entitled to tax income in all those situations where this income is linked to both states.
The most frequent case of double taxation is that of a person residing in state A and producing income in state B. In these cases, the treaties determine whether only the state of residence can tax income or whether the state as well ” source” of income can tax. Usually the state too “source” it can tax but it has limits. For example in the case of dividends, the state “source” is entitled to receive a withholding tax on dividends within a limit which is usually the 15%.
The treatment provided by the Conventions is usually more favorable than that which would otherwise apply. However, it is necessary to request the application of the rules and rates provided for by the Conventions through models that vary from state to state.
On the Revenue Agency website, you can find some models shared with other states and a generic model to request the application of the Conventions.
The link to the Revenue Agency website is: www.agenziaentrate.gov.it/portale/web/guest/schede/rimborsi/convenzioni-contro-le-doppie-imposizioni/modelli-e-istruzioni