As previously reported here, the EPO's Enlarged Board of Appeal has accepted a referral (G1/25) to consider whether the description of a European patent must be amended for consistency with any amended claims upheld in opposition or appeal proceedings. The Enlarged Board have now issued their preliminary opinion, and set a date of 8 May 2026 for oral proceedings to be held. The hearing will be livestreamed, so we can expect a large virtual audience of interested attorneys.
As a reminder, the questions referred to the Enlarged Board are:
- If the claims of a European patent are amended during opposition proceedings or opposition-appeal proceedings, and the amendment introduces an inconsistency between the amended claims and the description of the patent, is it necessary, to comply with the requirements of the EPC, to adapt the description to the amended claims so as to remove the inconsistency?
- If the first question is answered in the affirmative, which requirement(s) of the EPC necessitate(s) such an adaptation?
- Would the answer to questions 1 and 2 be different if the claims of a European patent application are amended during examination proceedings or examination-appeal proceedings, and the amendment introduces an inconsistency between the amended claims and the description of the patent application?
The (very brief) preliminary opinion suggests all questions are admissible, and the Enlarged Board see no need to reword any of them.
The answer to Q1 is, as frequently happens, unenlightening. The Enlarged Board suggests that there are two types of “inconsistency” between the claims and the description - those which cause non-compliance with the EPC, and those which do not. The first type necessitates adaptation of the description.
The second question has a more interesting answer. As noted in the referral, there are two lines of case law on this point, and the Enlarged Board prefer what we might call the “conventional” approach, that Art 84 EPC ("The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description") requires this approach. The preliminary opinion does not rule out that other provisions of the EPC may be relevant. The “unconventional” approach set out in T56/21 is dismissed: “The Enlarged Board is currently of the view that many of the conclusions of T 56/21 are inconsistent with decision G 1/24 and its underlying reasoning.” For more on G 1/24, see our earlier article.
Finally, the Board sees no reason why opposition and examination proceedings should be treated differently.
From this, it looks likely that amendments to the description will still be required in the future. But watch the livestream to hear counterarguments.