Responding to EPO Office Actions (Article 94(3) EPC): A Practical Guide
Last updated: 3 August 2026
An EPO office action — formally a communication under Article 94(3) EPC — gives you a fixed period, typically four months, to amend the application and/or argue why the examiner's objections are wrong. A strong response does three things: it answers every objection, it keeps every amendment safely within Article 123(2) EPC, and it frames inventive step in the problem-solution structure the examiner is required to apply.
This guide covers European examination practice. For US prosecution, see our guides on §102 rejections and §112 enablement.
Deadlines, Extensions, and Further Processing
- Standard period: the communication specifies the period — usually four months from deemed notification.
- Extension: a request filed before expiry normally secures an extension to six months in total; extensions beyond that are exceptional.
- Missed deadline: the application is deemed withdrawn. Further processing under Article 121 EPC is available as of right for this loss: request it within two months of the loss-of-rights communication, pay the fee, and complete the omitted act.
Diarise all three dates the day the communication arrives. The most expensive office action is the one answered in a panic during the further-processing window.
Reading the Communication: The Objection Types
| Objection | Legal basis | What the examiner is really saying |
|---|---|---|
| Novelty | Art. 54 EPC | One document discloses every feature of the claim, directly and unambiguously |
| Inventive step | Art. 56 EPC | Starting from the closest prior art, the skilled person would have arrived at the claim |
| Clarity | Art. 84 EPC | A term's scope cannot be determined, or the claim isn't supported by the description |
| Added matter | Art. 123(2) EPC | An amendment goes beyond the application as filed |
| Unity | Art. 82 EPC | The claims cover more than one inventive concept |
Answer every objection explicitly, even the ones you consider trivial. Unaddressed objections are the most common reason a second communication (or a summons to oral proceedings) arrives instead of a grant.
Amendments and Article 123(2) EPC
The EPO's "gold standard": amended subject-matter must be directly and unambiguously derivable from the application as filed. Practical discipline:
- Prefer literal basis. Lift wording from the claims or description as filed wherever possible, and cite the exact paragraph for every amendment in your reply.
- Beware intermediate generalisation. Extracting one feature from an embodiment while leaving behind features that were functionally linked to it is the classic 123(2) trap.
- Mind the 123(2)/123(3) squeeze after grant. Basis problems created during examination can become incurable later — another reason to amend conservatively now.
- Two-part form. Where the examiner requests it (Rule 43(1) EPC), place the features known from the closest prior art in the preamble and the distinguishing features after "characterised in that".
Inventive Step: The Problem-Solution Approach
EPO examiners assess inventive step in a fixed structure. Arguments written in that structure get traction; arguments written around it get boilerplate rebuttals. The four moves:
- Closest prior art. Usually the document sharing the most features and the same purpose as the claim. If the examiner picked a poor starting point, say so — but argue the case on their starting point too.
- Distinguishing features and technical effect. Identify precisely which claim features are absent from the closest prior art and what technical effect those features produce. Effects need support in the application as filed.
- Objective technical problem. Formulate it from the technical effect — without hindsight and without pointing to the solution.
- Could vs. would. The question is never whether the skilled person could have combined the documents, but whether they would have done so with a reasonable expectation of solving the objective technical problem. Attack the combination's motivation, its compatibility, and its expectation of success.
Structuring the Response
- Requests. State what you're filing (amended claims as main request; auxiliary requests if appropriate) and, as a precaution, request oral proceedings under Article 116 EPC — it preserves your right to be heard before any refusal.
- Amendments and basis. List each amendment with its exact basis in the application as filed.
- Novelty. Feature-by-feature rebuttal against the cited passages.
- Inventive step. Full problem-solution argument as above.
- Remaining objections. Clarity, formalities, description adaptation.
An AI-Assisted Workflow
A typical EPO response takes 6–12 attorney hours. The mechanical parts — extracting the objections, mapping cited passages to claim features, assembling the amendment/basis table, and producing a structured first draft — are exactly what AI does well, when the tool understands European practice.
With 23VIP's Reply Drafter:
- Import the communication and the cited prior art — EPO documents are imported directly.
- Review the objection analysis: the tool classifies each objection and maps cited passages against claim features.
- Generate the draft response: proposed amendments with basis citations, problem-solution-structured inventive step arguments, and feature-by-feature novelty rebuttals.
- Attorney review: refine the argumentation, check every basis citation against the application as filed, and settle the request strategy. The signing attorney owns the response.
Confidentiality note: office action work involves unpublished claim strategy. 23VIP runs on EU-hosted open-source models or frontier models configured not to train on your data — your choice per matter. See our trust page.
For the wider context on using AI in your practice — ethics, bar guidance, security evaluation — read the Attorney's Guide to AI Patent Drafting, or compare tools in Best AI Patent Drafting Tools 2026.