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

Amended documents must, provided that it is not irrelevant at the stage reached in the procedure, 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 any amendments do not offend against Art. 123(2) and Art. 123(3) (see D‑V, 6, H‑IV, 5.3 and H‑V, 2 and H-V, 3). It must also be checked that the patent, by the amendments themselves, does not contravene the requirements of the EPC (with the exception of Art. 82, see D‑V, 2.2). Forthe form of amended documents, see H‑III, 2.2 to 2.4.

Amendments of the description in opposition should be carried out 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.

Proprietors' observations, and any amendments they make, are communicated to the opponent(s) by the formalities officer without delay for information. No time limit for reply is set.