5.3 Filing of amended documents in reply to the notice of opposition 

In so far as relevant at the stage reached in the procedure, amended documents must be as complete as possible and drawn up in such a way as to allow the European patent, where appropriate, to be maintained without further delay in the amended version.

These considerations apply also to auxiliary requests in which the patent proprietor proposes amendments for consideration by the opposition division only if the division is unable to grant the main request, for example that the opposition is to be rejected. In both cases, however, it will be more convenient in certain circumstances to determine first the form of the claims, leaving purely consequential amendments in the description to be dealt with later (see D‑V, 5).

Care must be taken to ensure that no amendment contravenes Art. 123(2) and Art. 123(3) (see D‑V, 6 and H‑V, 2 and H-V, 3). For this reason, the patent proprietor should indicate the basis for any amendments in the original application documents and, if applicable, in the claims of the granted patent. It is also necessary to check that the patent, by virtue of the amendments themselves, does not contravene the requirements of the EPC (with the exception of Art. 82 and Rule 43(2), see D‑V, 2.2). The patent proprietor should therefore file their substantive observations regarding the allowability of the subject-matter of the patent as amended, in particular taking account of the grounds for opposition mentioned in the notice of opposition.

Amendments to the description in opposition should be made by submitting amended paragraphs replacing specific numbered paragraphs of the B publication of the patent. This allows the opposition division and the opponents to verify the amendments efficiently. For reasons of procedural economy, the filing of a completely retyped description should be avoided (see H‑III, 2.3). See also H‑III, 2.2 to H-III, 2.4 for the form of amended documents.

Observations and any amendments made by of the patent proprietor are communicated without delay by the formalities officer to the opponent(s) for information. No time limit for reply is set.