A Mere Title Is Not Enough: BPatG on the Minimum Requirements for a Filing Date (Sec. 35 German Patent Act)

In its decision of 25 February 2026 (case no. 11 W (pat) 28/25 – “Hygienic Lid for Cans”), the German Federal Patent Court (Bundespatentgericht, BPatG) clarified that the mere designation of an invention, without any indication of its technical features, is not sufficient to establish a filing date under Sec. 35(1) of the German Patent Act (PatG). The decision sharpens the requirements for the so-called “apparent description” (Anscheinsbeschreibung) and, at the same time, shows how generously appeals are construed in favor of applicants.

The Facts at a Glance

On 24 October 2024, the applicant submitted to the German Patent and Trade Mark Office (DPMA) only the first two pages of the official request form (P2007) – without a signature, without a description, and without patent claims. In the field “Designation of the invention,” she merely stated that a lid covers the top of the can, protects it from contaminants such as dust and insects, is easy to handle, contributes to hygiene, and comprises “five innovations”.

After a deficiency notice, the applicant filed a complete description with drawings only on 30 April 2025. Examining Section 27 of the DPMA rejected the application by decision of 27 May 2025 for lack of a description complying with the Patent Ordinance.

The Central Legal Question: When Does a Filing Date Arise?

Under Sec. 35(1) PatG, in addition to the applicant’s name and the request for grant, a filing date requires information “which appears to be a description”. The filing date marks the relevant date from which, for example, novelty and prior art are assessed – making it the single most important date of the entire application.

The BPatG contrasted two principles:

• Sufficient is any written formulation disclosing at least a minimal technical teaching, even in brief form within the “Designation of the application” field.
• Not sufficient is a mere designation of the invention without any outline of its technical features.

By way of illustration, the Senate referred to earlier case law, according to which the mere wording “brake light for a bicycle” does not establish the appearance of a description.

Why the Entry Was Insufficient in This Case

The Senate considered the form entry to convey only the information that the subject matter concerned a can lid. The further statements (protection against contamination, ease of handling, contribution to hygiene) merely described the goals pursued with the product, rather than concrete technical features. The reference to “five innovations” likewise failed to specify any technical teaching.

Consequence: As of 24 October 2024, the minimum requirements were not met; the application became effective only with the complete description filed on 30 April 2025.

The Filing Date Is Immovable

Notably, the court clarified that a validly established filing date is, in principle, unchangeable. Outside the exceptional cases of Sec. 35(2) and (3) PatG, it can be shifted neither at the applicant’s request nor ex officio. The applicant’s wish to have the subsequently filed documents “disregarded” in order to preserve the earlier date therefore came to nothing – the filing date arises solely through fulfilment of the objective requirements. This logic also corresponds to European law, under which the filing date under Art. 80 EPC changes only in the special cases of Rule 56 EPC.

A Generous Construction of the Appeal

A procedurally interesting point: the applicant had labeled her submission an “opposition” and a “request for examination under Sec. 44 PatG”. Nevertheless, the BPatG construed it as an admissible appeal under Sec. 73(1) PatG, because the intent to contest was unmistakable and the correct appeal fee number (401 300) had been indicated.

This applicant-friendly line aligns with the established BPatG practice in trademark matters, under which an appeal requires neither a specific request nor a statement of grounds, and in case of doubt the entire decision is deemed contested. A missing request is therefore harmless; the scope of the challenge is determined by interpretation.

Practical Consequences for Applicants

The DPMA must now decide the matter anew, with the Senate providing several pointers:

• The filing date is 30 April 2025, not the originally desired October date.

• Patent claims are still missing and must yet be filed.

• An abstract must be filed within 15 months of the filing date (Sec. 36(1) PatG).

• The missing signature does not affect the filing date and can be supplied later.

As a judicial review body in appeal proceedings, the BPatG examines whether the DPMA decision complies with formal and substantive law, and may confirm, amend, or – as here under Sec. 79(3) PatG – remit it.

Takeaway for Filing Practice

Anyone seeking to secure an early filing date should include at least a brief but technically concrete description at the time of filing – purely functional or promotional statements are not enough. Since the filing date is the reference point for novelty and inventive step, this early diligence often determines the patentability of the entire invention. For procedural uncertainties – such as the correct labeling of a legal remedy or filing a declaration of division before the DPMA or BPatG – early professional advice is recommended.