A taxpayer under the flat-rate scheme who receives compensation from a San Marino company that
applies a 20 percent withholding tax is not entitled to the tax credit for taxes paid abroad of
referred to in Article 165 Tuir.

This is what emerges from a reading of Resolution 36/E published yesterday, March 15, on the Revenue Agency’s website
, referring to an interpellation petition filed by a lawyer under the
lump-sum regime who receives fees from a company based in the Republic of San
Marino, incurring a 20 percent levy under Article 14 of the Convention against
double taxation signed between Italy and San Marino (ratified by Law 88/2013).

So pay attention to the type of convention signed between the two states to avoid double taxation because for some Conventions: you are not always entitled to the tax credit!