Article 123 EPC: Amendments

Text of Article 123 EPC

In plain English

Article 123(2) is the strictest rule in EPO practice and the one that most often surprises applicants from other systems. Any amendment, to the claims or the description, must be directly and unambiguously derivable, using common general knowledge, from the application as filed. This is the “gold standard” the Enlarged Board confirmed in G 2/10.

Literal basis is not required, but the bar is high. The most common problem is the intermediate generalisation: taking one feature from a detailed embodiment into the claim without the features it is functionally or structurally linked to. The Guidelines allow it only if the feature is not inextricably linked to the others and the overall disclosure justifies isolating it (H-V, 3.2.1). Combining features from separate lists or separate embodiments raises the same problem.

Disclaimers have their own rules. A disclaimer of subject matter that was disclosed is tested by the gold standard (G 2/10). An undisclosed disclaimer is allowed only to restore novelty over Article 54(3) art or an accidental anticipation, or to remove subject matter excluded for non-technical reasons; it must not remove more than necessary and must not become relevant for inventive step or sufficiency (G 1/03, G 1/16).

Article 123(3) applies after grant: the patent cannot be amended to extend the protection. Together with 123(2) it creates the inescapable trap described in G 1/93. If a limiting feature without basis was added before grant, removing it extends protection and keeping it is added matter, so the patent can only survive if the feature can be replaced by something with a basis that does not broaden the claim.

Corrections are not amendments. Under Rule 139 an obvious error in the description, claims or drawings can be corrected only if it is immediately evident that nothing else could have been intended (G 3/89 and G 11/91). Once the patent is granted, Rule 140 cannot be used to correct its text (G 1/10).

Key decisions

• G 2/10 (Disclaimer/SCRIPPS) : A disclaimer of disclosed subject matter infringes Article 123(2) if what remains in the claim is not directly and unambiguously disclosed in the application as filed.
• G 1/16 (Disclaimer III) : Undisclosed disclaimers are judged by the G 1/03 criteria, not the gold standard, and must not provide a technical contribution.
• G 1/03 (Disclaimer/PPG) : An undisclosed disclaimer may restore novelty over Article 54(3) art or an accidental anticipation, or remove non-technically excluded matter, and must not remove more than necessary.
• G 1/93 (Limiting feature) : A granted patent with an unsupported limiting feature cannot be maintained unamended, nor by deleting the feature if that extends protection: the inescapable trap.
• G 11/91 (Glu-Gln) : The description, claims and drawings may be corrected only within what the skilled person would derive directly and unambiguously from the documents as filed.

Common objections

Intermediate generalisation

Either add the features that were disclosed together with the one you took, or explain, citing passages, why the skilled person would see the feature as independent of them.

No basis indicated

Rule 137(4) requires you to identify amendments and their basis. A vague reference such as “see the description” is not enough and can lead to a one-month invitation.

Selection from lists

Picking one item from each of two lists of alternatives creates a combination that may not be disclosed. Look for an example or passage that discloses the combination itself.

Drafting and prosecution tips

• Write the description so that the features you may later claim are presented generally as well as in embodiments, with explicit statements that they can be used independently.
• Use lists of preferred features with clear hierarchies and combinations, and state ranges with intermediate end points.
• Keep a marked-up copy of each amendment against the application as filed, with page and line references, ready for Rule 137(4).
• Before grant, check that no limiting feature without basis has crept into the claims; after grant it may be impossible to remove.