Barely two years after its operational launch, the Unified Patent Court ("UPC") has already begun shaping a transnational doctrine of patent infringement by equivalence. Between late 2024 and mid-2025, four landmark first-instance decisions — Plant-e v Bioo (The Hague LD), Brussels LD CFI 376/2023, Mannheim LD CFI 471/2023, and N.J. Diffusion v Gisela Mayer (Paris LD) — established, refined, and finally harmonised the analytical framework for assessing functional equivalence under Article 26 UPCA and Article 69 EPC together with its Protocol on Interpretation.
The European framework resonates closely with the approach already codified in Article 89/5 of the Turkish Industrial Property Code, which defines the doctrine of equivalence in explicitly technical-functional terms. Under this provision, the protection conferred by a patent extends not only to what is literally claimed but also to elements that are equivalent to those expressed in the claims, provided that they perform substantially the same function in substantially the same way and produce substantially the same result.
This three-part formula ("function–way–result") creates a narrowly technical standard that excludes policy considerations such as fairness or foreseeability. Turkish courts, particularly the Ankara and Istanbul specialized IP courts, consistently apply this approach by examining whether the allegedly infringing feature carries out the same operation, by the same technical means, to reach the same outcome as the claimed invention. Only when all three conditions are met is infringement by equivalence recognized.
When Turkish Court's approach is compared to the UPC jurisprudence, the closest conceptual match is found in the Mannheim Local Division's decision of 6 June 2025 (CFI 471/2023). However, the Mannheim panel insisted that infringement by equivalence must be excluded whenever there is no technical-functional equivalence between the patent's feature and the alleged variant. Just like the Turkish Courts, the Mannheim LD has also focused purely on technical substitutability and did not consider whether the patentee deserves broader protection or whether third parties could have foreseen the variant.
By contrast, the earlier Plant-e v Bioo judgment of the Hague Local Division reflects a much broader and more policy-oriented conception of equivalence. Hague LD applied a four-question framework combining technical and normative considerations: whether the variant achieves the same technical result, whether extension of protection would be fair to the patentee, whether legal certainty for third parties would be preserved, and whether the variant remains novel and inventive over prior art.
The approach of Hague LD expands well beyond the Turkish Court's approach as it introduces balancing factors of fairness and foreseeability.
The Brussels Local Division took a step closer to the Turkish
Court's approach without a full alignment.
In its January 2025 ruling (CFI 376/2023), the Brussels judges
reduced the equivalence test to a functional-effect criterion,
asking only whether the modified means perform the same function or
at least achieve the same effect.
While this brings the analysis closer to the "function"
and "result" prongs of Article 89/5, it omits the
intermediate requirement that the element operate in the same
way.
Turkish Courts, by contrast, treats this "way" component
as indispensable; it ensures that mere similarity of purpose or
outcome is insufficient unless the technical mode of operation is
also equivalent.
Finally, the Paris Local Division's decision in N.J.
Diffusion v Gisela Mayer (1 August 2025, CFI 363/2024)
represents the culmination of UPC convergence toward the same
technical ideal, even if phrased more simply.
After reviewing Plant-e, Brussels, and
Mannheim, the Paris panel adopted what it called the
"lowest common denominator" test: whether the modified or
substitute means perform essentially the same function to achieve
essentially the same effect.
This rule omits explicit reference to the "same way"
criterion but, in practice, embodies the same spirit of
functional-result equivalence that underlies Turkish Court's
approach.
The Court denied equivalence precisely because the accused
product's component served a different function and therefore
produced a different effect. The reasoning is perfectly compatible
with the outcome a Turkish Court would likely reach.
In short, the Mannheim Local Division's reasoning most
faithfully mirrors the Turkish Court's approach. Both adopt a
purely technical and objective analysis that asks whether the
accused embodiment performs the same function, in the same manner,
with the same result.
The Brussels and Paris approaches can be viewed as partial
reflections of this rule, capturing its functional essence but
simplifying its structure.
The Hague's Plant-e framework, on the other hand, stands
furthest apart, introducing equitable and policy dimensions foreign
to the Turkish case law.
What is noteworthy is that, while the UPC initially experimented
with broader, policy-driven tests, its subsequent
evolution—especially in Mannheim and Paris—has
gravitated toward the strict technical equivalence model that the
Turkish legislature had already enshrined.
Thus, Turkiye's codified approach and the UPC's case law
are now converging upon a shared European standard: one that
defines equivalence not through notions of fairness or
foreseeability, but through objective functional identity within
the bounds of the claims.
First published by ManagingIP in Oct 31, 2025.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
