Are you excluded from patent exploitation? Find out how to protect yourself.
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Gabriele Rossi
When a patent has multiple holders, who gets to decide how to exploit it? This question lies at the heart of a recent decision by the Italian Supreme Court (Cassazione), Civil Section I, with ruling no. 4131/2025. Can one co-owner manufacture and sell an invention without the other’s consent? The Court clarified that co-ownership does not authorize unilateral action and that the exclusive rights granted by a patent must be respected by all co-owners. The most frequent disputes between co-inventors involve exploitation strategies, share transfers, and recognition of each individual’s contribution within the team. Without clear rules, the risk of conflict is extremely high.
It’s not uncommon for a patent to be co-owned by multiple inventors. Ownership can be split equally or distributed according to technical, economic, or creative contributions (see also: “Brevetto: cos’è e quando registrarlo?”). But what happens when one of the co-owners decides to produce and sell the invention without consulting the other?
That’s exactly what happened in the case brought before the Italian Supreme Court with ruling no. 4131, dated February 18, 2025. The dispute centered around an innovative spearfishing gun invented and patented by two individuals. However, only one of them began manufacturing and commercializing the product, without the consent of the other. The excluded partner did not accept the situation and took legal action to assert his rights.
The core question: who, among the two co-owners, had the right to economically exploit the invention?
The Italian Court addressed a straightforward legal question: can a co-owner exploit a patent without the consent of the other?
To answer, the Italian Court examined the principle of exclusivity that underpins patent rights. Article 66 of the Italian Industrial Property Code (CPI) grants the patent holder the exclusive right to implement the invention and profit from it. This exclusivity is the essence of patent protection, ensuring a competitive advantage for those who invest in innovation. But when ownership is shared, who can decide how the invention is used?
Article 6 CPI refers to the rules of joint ownership set out in the Italian Civil Code. However, applying such rules to patents is not straightforward: while real property can be used simultaneously by co-owners, a patent confers exclusive rights that are not easily divisible.
The Court has previously addressed this issue, paving the way to the current decision. As early as 1981, with Ruling no. 265, the Italian Supreme Court emphasized that patent co-ownership must follow certain joint ownership rules, requiring the consent of all co-owners for the sale or licensing of a patent.
However, the Court’s view has evolved. In Ruling no. 5281/2000, it applied Article 1102 of the Italian Civil Code, holding that if a single co-owner exploits the patent without the others’ consent, the remaining co-owners may suffer financial harm. Exclusive use by one party not only prevents others from benefiting but undermines the core principle of patent exclusivity.
In the spearfishing gun case, the Court of Appeal of Venice had adopted an approach akin to the rules of tangible property ownership, suggesting that one co-owner could act independently. The Italian Supreme Court overturned that view, reaffirming that the exclusivity right under Article 66 CPI must prevail:
“The unilateral (uti singulus) exploitation of the patent by a single party unquestionably alters its intended function. The legal protection originally conferred by the patent—when its exploitation was assigned to and exercised collectively by multiple parties, and the market accordingly attributed a specific value to the invention—is inevitably diminished when such joint use is replaced by individual exploitation.”
The result? The appellate ruling was annulled and the case sent back to a lower court. The Italian Supreme Court clearly stated that patent co-ownership does not authorize unilateral exploitation.
Anyone who has had a business partner knows that collaboration isn’t always easy. When a patent is shared, things get even more complicated—not just ideas, but rights, profits, and business strategies are at stake.
One of the most frequent problems involves differing expectations. One co-owner might want to commercialize the invention immediately, while the other prefers to wait and develop the product further or time the market strategically. Without a clear agreement, conflict is almost inevitable.
Another common issue involves licensing or selling one’s share. If one co-owner wants to transfer or license the patent and the other disagrees, a deadlock can arise that stalls the entire project.
The most delicate issue concerns recognition of contributions within the team. In innovative projects, roles are often loosely defined. Who had the idea? Who contributed most? Without clear definitions, disputes are likely—especially when the invention becomes commercially successful.
This challenge is well described in the article “What happens when the idea “belongs” to the minority partner?” by A. Canella, which highlights how intellectual property doesn’t automatically belong to the person with the idea and must be regulated from the outset.
Disagreements emerge when co-owners’ goals diverge. One might seek immediate profit; the other, long-term development. One might want to sell their stake; the other, to retain control. Without clear rules, conflict is unavoidable.
While the law offers protective measures, the best solution is prevention. A well-drafted co-ownership agreement and open communication can stop a promising collaboration from turning into a costly legal battle.
On the other hand, the Italian Supreme Court ruling clarifies an essential point: a patent co-owner cannot be excluded from the economic exploitation of the invention. This is not just a matter of fairness, but of protecting a strategic asset.
Disputes between co-inventors can severely devalue a patent. Internal conflict can freeze its exploitation, delay market entry, and deter investors. These risks can be avoided by adopting clear rules from the outset.
The first step is to formalize arrangements through a co-ownership agreement that clearly defines each inventor’s roles, rights, and obligations. Key aspects to regulate include:
A well-structured agreement reduces the risk of conflict and ensures the invention is commercially leveraged as effectively as possible. However, R&D projects evolve, and co-owners’ needs may shift. Therefore, a phased approach using legal instruments that accompany the development process is recommended.
Initially, a Memorandum of Understanding (MoU)—a non-binding document outlining collaboration terms and goals—can be useful (see also: “Guide to the mou: a key tool for startups and partnerships” by P. Lo Monaco). During prototyping or design, a Preliminary Agreement can anticipate obligations ahead of a definitive contract. Once all invention details and strategies are settled, the Final Agreement provides a binding framework for co-ownership.
Another often overlooked element is IP protection during development. Anyone involved in the design process might later claim patent rights, leading to disputes. To prevent this, a Prototyping and Development Agreement should clearly assign IP ownership from the outset.
This is especially relevant in academic research and technology transfer, where universities and companies collaborate on innovations. These dynamics are well explored in the article “The bridge between university and business: the strategic role of technology transfer”, which emphasizes the need to regulate IP ownership early to prevent disputes among researchers, institutions, and businesses.
Lastly, confidentiality is crucial when multiple parties work on a novel idea. Mismanagement of information can compromise patent value—or even prevent its registration. Therefore, it’s wise to use Confidentiality Agreements (CA) or Non-Disclosure Agreements (NDA) to safeguard the invention’s commercial value (see: “Accordi di riservatezza (NDA): come proteggere il valore delle informazion”).
A co-owned patent can become a strategic asset or a source of conflict. The difference lies in prevention and the ability to set clear rules before disputes arise.
Gabriele Rossi
