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Interest in Legal Protection for a Nullity Action – Part 5

The German Federal Patent Court (BPatG) denies the need for legal protection for a (retroactive) partial declaration of invalidity after expiry of the patent protection (BPatG, judgment of 5th October 2021, case no. 3 Ni 31/19)

Facts of the case

In the underlying case, the revocation action against the patent in suit (DE 10 2004 062 184) was not opposed. Instead, the patent proprietor acknowledged the claim, waived an assertion of claims against the invalidity plaintiff and caused the patent in suit to lapse by not paying the annual renewal fee due.


In the absence of any opposition from the patent proprietor to the invalidity action asserted, the BPatG made use of the possibility of deciding without oral proceedings (under Sec. 82 (2) Patent Act).

However, the BPatG dismissed the action on procedural grounds, since it had become inadmissible because of the expiry of the patent in suit. According to established case law of the Federal Court of Justice, the general interest in the invalidation of a patent ceases to exist if the patent has lapsed due to the passage of time or due to its surrender or the non-payment of the renewal fee. In such cases, a nullity action would only be admissible by way of exception if it is shown that the party bringing the action continues to have a need for legal protection. This must be affirmed if there is reason to fear that the plaintiff in the nullity action might still be exposed to claims for infringement of the patent in suit even after expiry of the term of protection. According to these principles, however, the invalidity plaintiff lacked the necessary need for legal protection in the present case, since they had not submitted any evidence in this respect. Rather, the invalidity plaintiff had sued solely out of popular interest, without having been directly affected themselves.


The BPatG’s decision is convincing, considering Parts 1-4 of the series of articles on the most recent decisions of the Federal Court of Justice on the interest in legal protection for a nullity suit after the expiry of the patent term. Here, it was shown that, in the opinion of the Federal Court of Justice, in principle not too strict standards may be applied to the need for legal protection. However, since in the specific case the nullity action was filed solely in the popular interest and there was no reason for the nullity plaintiff to be concerned that they would be held liable for their own actions based on earlier patent infringement under the already expired patent in suit, there was an insufficient need for legal protection. Therefore, when filing and substantiating a nullity action, one must take care to present one’s own interest in addition to the substantive grounds for revocation in order not to run the risk that the action will immediately be dismissed as being inadmissible.

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Dr. Christian Meyer



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