Description amendments: Referral to EPO’s Enlarged Board of Appeal now imminent

An EPO Board of Appeal is expected imminently to request clarification from the Enlarged Board of Appeal concerning whether and to what extent amendment of the description of an application or patent to conform with the claims is required.


A long-standing quirk of European patent practice is the requirement for applicants to amend the description of an application for conformity with the claims. For many years, the EPO tolerated applicants making token efforts towards this, typically allowing the replacement of terms such as “embodiment” and “invention” with neutral language only in passages which were most clearly outside the scope of the claims.

In early 2021, the EPO’s revised Guidelines for Examination made this requirement more onerous, insisting that subject matter not covered by the claims be either deleted or explicitly demarcated as not forming part of the claimed invention. In practice, many applicants found this requirement to be stringently enforced by the EPO’s Examining Division, requiring substantial amendments to the description, even in borderline cases.

A major concern with the EPO’s increasingly strict approach to description amendments arises from the impact that such amendments can have on both claim interpretation and the scope of protection under the doctrine of equivalents in subsequent infringement proceedings. The potential impact of equivalence in UK patent law increased substantially following the UK Supreme Court’s decision in Actavis v Eli Lilly [2017] UKSC 48, and it has been an abiding principle of the national law of other EPC contracting states, such as Germany.

A more recent concern associated with the EPO’s strict position of description amendments arises from a decision of a Board of Appeal that, in opposition proceedings, claims should be interpreted in view of the description of the patent as granted rather than the description of the application as filed (see T450/20).

In view of these risks, some applicants and proprietors have resisted demands to amend descriptions, resulting in a number of decisions of the Boards of Appeal concerning description amendments. Some Boards have found that there is no legal basis for the requirement to amend the description (T1989/18, T1444/20, T2194/19, T0121/20), while others found basis in Articles 84 and 69 EPC (T1024/18, T2766/17, T1968/18 and T3097/19).

Despite a slight softening of the Guidelines for Examination in 2022, the growing divergence in approach being adopted by different Boards of Appeal meant that the issue of description amendments was unlikely to blow over. Clarity from the Enlarged Board of Appeal will be welcomed by many.


Hoffmann-La Roche appealed the Examining Division’s decision to refuse EP3094648 after Roche would not accept the Examining Division’s request to delete claim-like clauses in the description.

Both the appellant (Roche) and Board of Appeal (3.3.04) are the same as in T1989/18, which produced the landmark decision in which the Board found no legal basis requiring the amendment of the description. Interestingly, Roche’s appeal in this case was filed before the tightening of the Guidelines for Examination in 2021 and the ensuing controversy over description amendments.

In July 2023, this Board of Appeal issued a lengthy communication outlining the legislative backdrop to description amendments and proposing a referral of the following question to the EPO’s Enlarged Board of Appeal:

Is there a lack of clarity of a claim or a lack of support of a claim by the description within the meaning of Article 84 EPC if a part of the disclosure of the invention in the description and/or drawings of an application (e.g. an embodiment of the invention, an example or a claim-like clause) is not encompassed by the subject-matter for which protection is sought (“inconsistency in scope between the description and/or drawings and the claims”) and can an application consequently be refused based on Article 84 EPC if the applicant does not remove the inconsistency in scope between the description and/or drawings and the claims by way of amendment of the description (“adaptation of the description”)?

In response, Roche agreed that a referral to the Enlarged Board was necessary, thereby essentially guaranteeing that such a referral will be made in the coming months. Roche did, however, propose certain amendments to the proposed question, predominantly to encompass situations in which amendment of the description is required after grant, for example during EPO opposition proceedings.


A referral to the Enlarged Board of Appeal may be good news for applicants as many will welcome clarification of the requirements for description amendments. Currently, many applicants may not have the appetite or funds to challenge an Examiner’s strict adherence to the current Guidelines, given that the outcome on any appeal will be heavily dependent on the preferences of the responsible Board. A decision from the Enlarged Board will hopefully provide increased uniformity of approach.

Of course, many applicants will be hoping that the Enlarged Board does away with the requirement for description amendments altogether, which would bring the EPO into line with the majority of other jurisdictions. However, we suspect that the EPO’s recent commitment to increase patent ‘quality’, and perhaps the view that an amended description results in greater legal certainty for third parties, will rule out such a drastic change.

Once a referral is made to the Enlarged Board, applicants will be able to request that examination proceedings are stayed if the outcome of examination is entirely dependent on the answer to the referred question(s). It is envisaged that applicants wishing to delay the grant of their application could therefore request appropriate amendment of the description for the sole purpose of ensuring that proceedings are stayed. Provided that the scope of the referred question(s) includes opposition proceedings (as requested by Roche), similar tactics could be employed in some circumstances by proprietors wishing to postpone a decision of the Opposition Division.


A referral to EPO’s Enlarged Board of Appeal concerning amendments to the description of an application or patent is now imminent.
Watch this space for further updates.
Opportunities to postpone grant of a patent or even the decision of an Opposition Division by requesting a stay may arise if the referral goes ahead.