Patent Prosecution at the DPMA and EPO

Patent prosecution in Germany: two routes to protection

Patent prosecution is the process of obtaining a patent, from drafting and filing the application through examination to grant and, if necessary, opposition. Applicants seeking protection in Germany have two main routes: a national German patent granted by the German Patent and Trade Mark Office (Deutsches Patent- und Markenamt, DPMA) under the Patent Act (Patentgesetz, PatG), and a European patent granted by the European Patent Office (EPO) under the European Patent Convention (EPC), which can be validated in Germany or given unitary effect.

Many companies use both, often starting with a German filing to secure priority and following with a European or international application within twelve months.

The choice of route is a business decision: it depends on the markets that matter, the budget, the speed required and the litigation strategy — including whether patents should be enforceable before the Unified Patent Court (UPC). This note explains the key features of each route and how to combine them, with a focus on the technical fields in which German industry is most active: mechanical and electrical engineering, physics, automotive, chemistry and life sciences.

The German route: DPMA examination

A German patent application is filed with the DPMA. Key features of DPMA patent prosecution are:

• Deferred examination: examination starts only on request, which the applicant (or any third party) can file up to seven years after the filing date (§ 44(2) PatG). This allows applicants to keep options open at low cost.
• Search request: the applicant can request a search report on the state of the art and a preliminary assessment of patentability (§ 43 PatG), useful for deciding on foreign filings within the priority year.
• Publication: applications are published 18 months after the filing or priority date (§ 31(2) PatG), after which third parties can inspect the file and submit prior art.
• Language: proceedings are in German; applications filed in another language require a German translation within the statutory period.
• Opposition: after grant, anyone can file an opposition within nine months of publication of the grant (§ 59(1) PatG). Later challenges require a nullity action at the Federal Patent Court.

The German national route is comparatively inexpensive and examination by the DPMA is regarded as thorough. Third parties can also file observations on the state of the art during examination (§ 43(3) PatG), which competitors use to influence the scope of a pending application without starting formal proceedings. It is attractive for applicants whose key market is Germany and for securing an early priority date, including for utility model branch-offs; see our insight on utility models in Germany.

The European route: EPO examination, validation and unitary effect

A European patent application is filed with the EPO (directly or as a regional phase of an international PCT application). The EPO conducts a search and, after the applicant requests examination, a substantive examination for the EPC states designated. After grant, the European patent becomes a bundle of national patents, which must be validated in the countries chosen — or, for participating EU Member States, the proprietor can request unitary effect, creating a single European patent with unitary effect covering all participating states. The request for unitary effect must be filed within one month of publication of the mention of grant.

The international route: PCT applications

For applicants targeting markets beyond Europe, an international application under the Patent Cooperation Treaty (PCT) defers national and regional decisions for up to 30 or 31 months from priority. The application receives an international search report and a written opinion on patentability, which helps decide where to continue. The EPO frequently acts as International Searching Authority for European applicants. On entering the European regional phase, the application continues as a European application; a German national phase is also possible. The PCT route adds cost at the start but buys time to test the market and secure funding before incurring national costs in many countries.

Combining routes: double protection and portfolio design

German law prohibits double protection only in a specific situation. A German patent loses its effect to the extent it protects the same invention as a European patent with the same priority granted for Germany, if that European patent has been opted out of the UPC's exclusive jurisdiction (Article II § 8 IntPatÜbkG). For European patents that remain within the UPC system and for unitary patents, a parallel German national patent can coexist. This allows applicants to hold a German patent enforceable in the national courts alongside a European or unitary patent enforceable at the UPC — a useful hedge against central revocation.

Typical portfolio structures include:

1. German first filing, then EP or PCT: secures priority quickly and cheaply; German search results inform the international strategy.
2. Unitary patent plus German national patent: combines broad coverage with a national fallback in case the unitary patent is revoked centrally.
3. Classic EP validated in key states, opted out: for crown-jewel patents where central revocation risk is a concern; then no parallel German patent for the same invention.
4. Utility model branch-off: to obtain quick enforceable protection in Germany while the patent application is pending.

Patent prosecution across technical fields

Patentability requirements are harmonised — novelty, inventive step, industrial application and sufficient disclosure — but practice differs between technical fields.

Electrical engineering, physics and software

Computer-implemented inventions are patentable at both offices if they solve a technical problem with technical means; features without technical character do not contribute to inventive step. Drafting should anchor claims in technical effects, such as control of a physical process or improved use of hardware. Standards-related inventions in telecommunications call for claims that read on standard-compliant implementations, which matters later in licensing and SEP litigation; see our insight on SEP and FRAND disputes.

Mechanical engineering and automotive

Claims often focus on structural features and interactions of components. Auxiliary requests and fallback positions in dependent claims are important, because opposition and nullity attacks frequently target inventive step through combinations of prior art.

Chemistry, pharmaceuticals and biotechnology

Sufficiency of disclosure, experimental data supporting the claimed effect and selection inventions are central. Second medical use claims and supplementary protection certificates (SPCs) extend protection for medicinal products. The EPO's case law on plausibility and post-filed evidence is particularly relevant.

Opposition, limitation and post-grant strategy

Patent prosecution does not end at grant. EPO opposition within nine months of grant (Article 99 EPC) is a powerful central attack, and German oppositions at the DPMA follow the same nine-month period. Proprietors can also limit their patents centrally to strengthen them before enforcement. Monitoring competitors' grants and filing oppositions is often cheaper than nullity actions later. Proprietors facing an opposition should prepare auxiliary requests with narrower claims, because an amended patent that still covers the commercially relevant products is often a good outcome. For the interaction with litigation, see our insight on the injunction gap and bifurcation.

Ownership, inventors and employee inventions

Before filing, the applicant must hold the right to the invention. In Germany, inventions made by employees in the course of their work are service inventions under the Employee Inventions Act; the employer must claim them and pay compensation. Inventor naming, assignments from contractors and university collaborations should be documented before filing. Our insight on employee inventions under the ArbnErfG explains the rules.

Inventorship and AI-assisted inventions

Both the DPMA and the EPO require an inventor to be named, and the inventor must be a natural person; an AI system cannot be named as inventor. Where AI tools are used in research and development, the question is which humans made the inventive contribution. Applicants should document the human contributions — problem definition, selection and evaluation of results, and technical implementation — so that inventorship and entitlement can be shown. Employee-invention rules apply to the human inventors in the usual way, and confidentiality obligations should cover data and prompts entered into AI tools before filing, as disclosure before the filing date can destroy novelty.

Practical checklist for patent prosecution

1. Search before drafting: a freedom-to-operate and novelty search helps shape claims and avoids wasted costs.
2. Secure ownership: employee inventions claimed, contractor and university assignments signed.
3. File early to secure priority, ideally before any publication, trade fair presentation or customer demonstration.
4. Draft claims with enforcement in mind: identify how infringement will be proven and by whom.
5. Use the priority year to decide on European, PCT and other foreign filings.
6. Decide on unitary effect, validation and opt-out at grant, aligned with the portfolio strategy.
7. Monitor competitors' grants and use oppositions within nine months.

Costs and timing

Costs arise at filing, search, examination, grant and in annual renewal fees, plus attorney fees for drafting and responding to office actions. The German route allows costs to be deferred through the seven-year examination window. The European route concentrates costs around examination and validation; unitary effect can reduce renewal and translation costs where many EU countries are needed. Accelerated processing is available at both offices in certain circumstances, which can matter when a competitor is already copying the product.

Budgets should be planned per patent family over a five- to ten-year horizon. Portfolio reviews every one or two years help to drop families that no longer support the business, reducing renewal costs, and to identify gaps where new filings are needed. For start-ups and SMEs, the timing of costs often matters as much as the total: deferring examination in Germany and using the PCT can align patent spending with funding rounds and market entry.

How TRW & Co helps with patent prosecution strategy

Patent prosecution before the DPMA and EPO is conducted by patent attorneys; we work alongside them on the legal and strategic side. We advise companies on filing strategies that support enforcement and transactions, on ownership and employee-invention issues before filing, on the choice between unitary effect, national validation and opt-out, and on oppositions and limitation proceedings in the context of disputes. We also review patent portfolios in M&A and licensing. See our pages on patent litigation and the Unified Patent Court, or contact us.