On when service of a tax demand is complete, the case law draws distinctions. Knowing when the second registered letter is not required shapes the defence strategy.
Whether service was properly effected is often the first thing to check on receiving a cartella. The rules distinguish direct service by post from service through a process server or officer, each completed under different rules.
Where direct service is effected by handing the document to the addressee or to a person entitled to receive it, service is complete without the second registered letter of notice, a step required instead in specific cases where the addressee cannot be found or the document is handed to someone else.
Challenging a defect in service calls for reconstructing precisely how the document was served and what the supporting records show (the relata di notifica, the acknowledgements of receipt). Rigorous analysis avoids unfounded objections and gives weight to those that really decide the case.