In European patent practice, unity of invention is a distinct concept from the number of independent claims present in a European patent application. However, these concepts can often overlap or be misunderstood.
This article digs into some of the legal aspects of unity of invention and the number of independent claims, and provides some tips for navigating these aspects.
What is unity of invention?
Unity of invention relates to the general principle that a European patent is granted for each invention separately.
For example, this principle assists to provide equal treatment of applicants of European patent applications since any applicant is entitled to the same service (e.g., a European patent for a single invention) for the same official fees [1].
An article with further details regarding unity of invention is linked here.
Can a European patent application contain more than one independent claim in the same claim category (product, process, apparatus or use)?
Yes, but only under specific circumstances.
The specific circumstances are governed by Rule 43(2) of the European Patent Convention (EPC) [2].
An article with further details regarding these specific circumstances is linked here.
Does Rule 43(2) EPC prejudice unity of invention of a European patent application?
No.
Rule 43(2) EPC explicitly states that this requirement is without prejudice to unity of invention. In other words, the claims are required to meet the requirements of unity of invention regardless of whether the claims fall under the specific circumstances of Rule 43(2) EPC [2].
When can claims meet the requirements of Rule 43(2) EPC without having unity of invention?
An example of this can occur where the claims include a single independent claim that lacks novelty.
In this example, since the claims include only a single independent claim, the claims comply with Rule 43(2) EPC.
However, if the dependent claims include two or more claims having different novel features over the cited prior art, a lack of unity between these dependent claims can occur.
When can claims have unity without meeting the requirements of Rule 43(2) EPC?
An example of this can occur where the claims include multiple independent claims in the same claim category that each include:
- one or more of the same or corresponding special technical features (e.g., feature A); and
- one or more of the same other features (e.g., feature B).
An example of this might include:
- a first independent claim that is an apparatus comprising features A + B; and
- a second independent claim that is an apparatus comprising features A + B + C.
Since these independent claims include one or more of the same or corresponding special technical features (e.g., feature A), the claims have unity.
However, since the second independent claim contains all of the features (A + B) of the first independent claim, a European patent examiner may consider the second independent claim to include undue repetition of wording thereby lacking conciseness. This objection is often raised under Rule 43(2) EPC in combination with Article 84 EPC (clarity and support).
This type of objection may be resolved by amending the second independent claim to be dependent on the first independent claim (e.g., by referring to only feature C in the dependent claim).
How can we help?
As specialists in European patent practice, we can prepare and prosecute European patent applications to help you attempt to take of advantage of unity of invention and to maximise the number of independent claims in a European patent application.
Please get in touch with Thomas Measures – Appleyard Lees if you would like to discuss this further.
References:
[1] https://www.epo.org/en/legal/guidelines-epc/2025/f_v_1.html
[2] https://www.epo.org/en/legal/epc/2020/r43.html
