There is no specific obligation to use these forms. They have been set up by the Italian Revenue Agency to let non-residents know what information is requested. Taxpayers can personalize the forms and enclose attachments.
In case of refund claims, taxpayers have to submit the request within 48 months
from the date on which the tax was paid or withheld at source and send it to:
Agenzia delle Entrate – Centro Operativo di Pescara – via Rio Sparto, 21 65129 Pescara, Italia
In some cases and when the withholding agent agrees, the same forms can also be used for the direct application of the conventional benefit.