July 2025 The question of legal basis for the EPO’s description amendment requirement has been the subject of debate for a long time. However, a recent referral to the Enlarged Board of Appeal (G 1/25) has set the stage for finally settling this matter.
Background
As reported in several of our earlier articles, it has long been the practice of the European Patent Office (“EPO”) to require the description of a European patent application to be amended upon allowance of the claims to ensure that the description does not disclose the invention more broadly than the claims. However, the way in which this practice has been implemented has become increasingly strict in recent years.
Furthermore, this practice is at odds with the practices of many other patent offices around the world, and is widely disliked by applicants and their representatives alike because of the laborious burden it imposes on them and the risk of deleting technically important subject matter it creates. The legal basis relied upon by the EPO to impose this requirement is also considered by many to be questionable, and has been the subject of extensive debate in recent years.
It was widely expected that the Board of Appeal in T 56/21 would refer this matter to the EPO’s Enlarged Board of Appeal (see our article of November 2023 for additional detail), however that referral failed to materialise, with the Board instead holding that there is no legal basis for the EPO’s description amendment requirement and ordering that the applicant should be granted a European patent without amendments to the description being required.
Thus, at present, there remains a conflict in the case law, with some Boards of Appeal holding that there is legal basis for the EPO’s description amendment requirement, and others holding that there is not.
Recent Developments
To the delight of those of us practising European patent law, Board of Appeal no. 3.3.02 has referred to the Enlarged Board of Appeal (as G 1/25) three questions regarding legal basis for the controversial description amendment requirement in its recent decision, T 697/22, issued earlier this week.
The questions referred 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 first question essentially asks whether the EPC provides legal basis for the description amendment requirement in cases where the claims of a European patent are amended post-grant, i.e. during EPO opposition proceedings or appeal proceedings arising therefrom.
The second question then essentially asks which Articles/Rules of the EPC provide such legal basis, if indeed such legal basis exists.
The third question then reformulates the first question to ask about pre-grant proceedings, essentially asking whether there is legal basis (and, if so, which Articles/Rules of the EPC provide the required basis) for requiring the applicant to amend the description in cases where the claims are amended during examination of a European patent application, or during appeal proceedings arising therefrom.
Conclusions
We, along with patent attorneys across Europe, are hopeful that the Enlarged Board of Appeal will now settle this issue once and for all.
However, it is noteworthy that an answer to the third question does not appear to be necessary for a decision to be reached in the case giving rise to the referral. There is therefore a significant risk the Enlarged Board will hold that question inadmissible, despite this being the question many applicants and their representatives will really be hoping for an answer to. Having said that, the Board in T 697/22 appears to recognise this, stating in its decision that it is nonetheless “useful to refer” the third question “to the Enlarged Board of Appeal” as a fundamental question of law that affects “the practice of the boards and all other departments of the EPO”.
We therefore hope the Enlarged Board of Appeal will agree and issue a decision finally bringing this debate to a close.
