Necessary Joinder in Remand Proceedings: The Court of Cassation Establishes Limits with Order No. 15400 of 2025

Civil procedural law is a constantly evolving field, and rulings by the Court of Cassation play a fundamental role in defining the boundaries and interpretations of legal norms. A matter of particular relevance, which often generates debate and uncertainty, concerns necessary joinder, especially when it arises within the complex dynamics of remand proceedings. In this context, Order No. 15400 of June 9, 2025, issued by the Second Section of the Court of Cassation, presided over by Dr. M. M. and with Dr. A. M. as rapporteur, offers essential clarifications and establishes indispensable firm points for judicial practice.

The ruling, which saw C. (represented by lawyer D. G.) pitted against F. (represented by lawyer A. P.), quashed and remanded a previous decision by the Court of Appeal of Genoa dated September 11, 2020. The core of the issue revolved around the possibility of objecting to or ex officio noticing the lack of full joinder in remand proceedings, when this aspect had not been raised or noticed in the appeal to the Court of Cassation. Let's examine in detail the implications of this important decision.

Necessary Joinder and its Procedural Relevance

Necessary joinder, governed by Article 102 of the Code of Civil Procedure, occurs when the decision of a case can only be rendered in relation to multiple parties, who must therefore sue or be sued in the same proceeding. Its correct observance is fundamental for the validity of the proceedings and the effectiveness of judicial protection, as it aims to avoid useless or conflicting rulings. Failure to ensure full joinder generally results in the nullity of the proceedings or the need to order the joinder of parties.

However, the procedural path is not always linear, and the remand phase, following a decision by the Court of Cassation, presents peculiarities that require careful evaluation. The Court of Cassation, with the order in question, sought to curb excessive flexibility, prioritizing the stability of judgments and legal certainty. The guiding principle, clear and peremptory, deserves careful analysis:

In remand proceedings from the Court of Cassation, the lack of full joinder due to an original requirement for necessary joinder (Art. 102 c.p.c.) cannot be objected to or noticed ex officio when such an issue was not raised in the appeal to the Court of Cassation and noticed by the legitimacy judge, as it must be presumed that the adversarial principle was deemed to be fully respected at that stage. Consequently, only those who were parties in the initial proceedings before the Court of Cassation can and must participate in the remand proceedings and in any subsequent legitimacy proceedings as necessary co-parties.

This principle crystallizes a fundamental rule: once the proceedings have reached the Court of Cassation, and this court has not noticed or been prompted to notice an issue of necessary joinder, a form of "preclusion" is established. In other words, it is presumed that the Supreme Court implicitly considered the adversarial principle to be fully respected. This presumption prevents the issue from being raised subsequently in the remand proceedings or in any further appeal to the Court of Cassation.

Practical Implications and Legal Foundations

The consequences of this interpretation are significant. Firstly, it reinforces the principle of procedural economy and the stability of decisions. Allowing a necessary joinder issue to be raised at such an advanced stage of the proceedings, after the legitimacy judgment, would mean reintroducing elements of uncertainty and potential delays, partially undermining the nomophylactic function of the Court of Cassation. The ruling connects to the principles of Articles 394 and 331 of the c.p.c., which respectively govern remand proceedings and appeals involving multiple parties.

This position of the Court of Cassation is not entirely new, but Order No. 15400/2025 reiterates it forcefully, also referencing consistent precedents (such as No. 21096 of 2017). This underscores the consolidated trend in legitimacy jurisprudence aimed at preventing abuses or strategic delays. For lawyers, this means that attention to the correct integration of the adversarial principle must be paramount from the earliest stages of the proceedings and, in any case, must be brought to the attention of the Court of Cassation if a violation is believed to have occurred.

• **Procedural Stability:** The decision aims to consolidate procedural positions defined up to the legitimacy stage.
• **Procedural Preclusion:** A preclusion is created regarding the issue of necessary joinder not noticed by the Court of Cassation.
• **Parties in Remand:** In remand proceedings, only those who were parties in the Court of Cassation proceedings can and must participate, unless specific orders are issued by the legitimacy judge.
• **Role of the Lawyer:** It imposes a scrupulous verification of the correct integration of the adversarial principle at every level of judgment, with particular attention to the legitimacy stage.

Conclusions

Order No. 15400 of 2025 by the Court of Cassation represents an important warning for all legal professionals. It clearly reiterates that the issue of necessary joinder, if not raised or noticed in the legitimacy proceedings, can no longer be re-proposed in the subsequent remand proceedings. This principle not only ensures greater stability and speed in proceedings but also emphasizes the importance of rigorous management of procedural exceptions in the higher courts.

For parties and their legal counsel, the lesson is clear: maximum diligence in verifying and, if necessary, raising issues of necessary joinder is crucial. Ignoring this aspect before the Court of Cassation means implicitly accepting the integrity of the adversarial principle, precluding any future challenge on this point. This is a ruling that, despite its technicality, contributes to outlining a more certain and predictable procedural framework, benefiting all parties involved in civil justice.