Splitting Claims in Opposition: Board 3.5.01 Sidelines T 1138/02 on Rule 80 EPC
Can a patent proprietor replace a single granted independent claim with multiple independent claims during opposition? In T 0561/23, the Board of Appeal says yes, explicitly rejecting older restrictive case law.
If you want to start an argument amongst European patent attorneys, just ask whether a proprietor can replace a single granted independent claim with multiple independent claims during opposition. The opposition division often views this as a stealthy attempt to introduce lack of unity, while proprietors argue it is their fundamental right to defend their granted dependent claims. In T 0561/23, Technical Board of Appeal 3.5.01 provides a refreshingly clear answer, explicitly sidelining restrictive older case law.
The blind system and the novelty trap
The patent at issue, EP 2 755 318, relates to a blind system featuring a brushless motor and integrated control electronics. During opposition proceedings, the granted independent claim fell victim to a novelty attack based on an Article 54(3) EPC prior art document (D6).
To salvage the patent, the proprietor filed several auxiliary requests. During oral proceedings before the Board, after the Board changed its preliminary opinion on novelty based on the opponent's deepened arguments, the proprietor filed Auxiliary Request XIb' (reasons 13 and 17). This request replaced the single granted independent claim with a claim containing two independent alternatives, each corresponding to a different granted dependent claim (reasons 19–20).
The Rule 80 EPC dilemma
The opposition division had previously rejected similar requests, relying on the rather strict decision T 1138/02. According to that older decision, replacing an independent claim with multiple independent claims is only permissible if the alternatives relate to a common generic feature. Because the proprietor's alternatives in this case diverged—one relating to control modes and the other to the number of external connections—the opposition division concluded the amendment was not occasioned by a ground for opposition under Rule 80 EPC (reasons 21).
The opponent further argued that allowing such divergent alternatives would effectively bypass the unity of invention requirement, especially since one alternative merely incorporated an optional "and/or" feature from a granted dependent claim (reasons 23).
Sidelining restrictive case law
The Board of Appeal firmly rejected the opposition division's approach. In a robust defense of the proprietor's procedural rights, the Board held that it is generally permissible to replace a fallen independent claim with multiple independent claims, provided they are directed to subject-matter already defined in the granted dependent claims (reasons 22).
The Board explicitly dismissed T 1138/02 as an isolated decision (original in German: Einzelfallentscheidung) that should generally not be followed (reasons 22). The reasoning is eminently practical: a patent proprietor must be allowed to maintain potentially allowable subject-matter that was already present in the granted claim set.
Addressing the opponent's concerns about diverging inventions, the Board noted that while a lack of novelty in claim 1 might reveal a lack of unity among the dependent claims, lack of unity is simply not a ground for opposition (reasons 24). Furthermore, because a proprietor cannot file a divisional application during opposition proceedings, there is no justification for forcing them to choose between parallel dependent claims when defending their patent (reasons 24).
Having found the claims novel and compliant with Rule 80 EPC, the Board remitted the case to the opposition division under Article 111 EPC for the assessment of inventive step (reasons 38).
Practical implications
This decision is a significant win for patent proprietors. It confirms that you can safely deploy multiple independent claims (or alternative independent features) in opposition to defend different fallback positions, provided those positions were anchored in the granted dependent claims.
For opponents, the message is equally clear: you cannot use Rule 80 EPC as a backdoor to raise unity objections. If a proprietor splits their claim to defend against a prior art attack, you must be prepared to attack the novelty and inventive step of each resulting alternative on its own merits. Finally, when drafting European patent applications, this decision underscores the immense strategic value of including a diverse array of parallel dependent claims—they are your independent lifeboats when the main claim sinks.