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The Court of Appeal applies the brakes on added matter


Zack Mummery takes a look at how added matter is dealt with in the UK courts, with a particular focus on the recent Court of Appeal decision in AP Racing Ltd v Alcon Components Ltd.

Added matter is a topic of significant importance in patent law in the UK, Europe and further afield. Broadly speaking, added matter refers to amendments that introduce subject matter extending beyond the application as filed. The prohibition of such amendments stems from ensuring legal certainty for third parties, as well as preventing applicants from gaining an unwarranted advantage by amending their patent or patent application.

Amendments that add matter are prohibited under UK law as well as under the European Patent Convention (EPC). Under the EPC, amendments that add matter are a ground for opposition, and under both legislative frameworks, amendments that add matter are considered as a ground for revocation.

Added matter is a large and often subtle legal topic, with different jurisdictions approaching its assessment in different ways and with different levels of strictness. For example, the EPO are noted as having a particularly strict view on added matter, while some consider the US to approach the issue more leniently. While we hear lots on how the EPO assess added matter, I feel the approach of the UK courts is not so widely reported.

The UK Approach

S72(1)(d) of the UK Patents Act sets out the following ground as one of five grounds by which a patent may be revoked.

The matter disclosed in the specification of the patent extends beyond that disclosed in the application for the patent, as filed, …

Art 138(1)(c) EPC sets out the following as one of five grounds by which a European patent may be revoked.

The subject matter of the European patent extends beyond the content of the application as filed …

The cases Bonzel and Schneider (Europe) AG v Intervention Ltd [1991] and Richardson-Vicks Inc.’s Patent [1995], provide a good starting point for how the UK courts assess added matter.

In Bonzel and Schneider v Intervention Ltd, Aldous LJ set out the following three-step test.

The task of the court is threefold:

  1. to ascertain through the eyes of the skilled addressee what is disclosed, both explicitly and implicitly in the application;
  2. to do the same in respect of the patent as granted;
  3. to compare the two disclosures and decide whether any subject matter relevant to the invention has been added whether by deletion or addition. The comparison is strict in the sense that subject matter will be added unless such matter is clearly and unambiguously disclosed in the application either explicitly or implicitly.

This three step test has been applied in a number of subsequent cases, including AP racing Ltd. v Alcon Components Ltd. which is discussed below.

Neatly summing up how to assess added matter, Jacob J (as he then was) in Richardson Vick’s patent proposed the following test:

I think the test of added matter is whether a skilled man would, upon looking at the amended specification, learn anything about the invention which he could not learn from the unamended specification.”

AP Racing Ltd v Alcon Components Ltd [2014] EWCA Civ 40

This case was an appeal from a decision of the Patents County Court (as it then was) to revoke AP racing’s patent on the grounds of added matter. The Court of Appeal’s decision provides a good overview of the way UK courts are currently assessing added matter.

The impugned patent related to disk brakes and in particular, disk brake callipers. The claim in question included the following features, numbered for easy reference.

  1. A body for a fixed type disc brake calliper,
  2. The body comprising a mounting side limb and a non mounting side limb,
  3. Eeach limb having two or more hydraulic brake cylinders suitable for receiving corresponding hydraulic brake pistons,
  4. The limbs being rigidly inter-connected at either end by spaced bridging members and profiled to define a shaped housing portion about each cylinder,
  5. Each of the limbs having a peripheral stiffening band extending in a longitudinal direction about and interconnecting outer lateral end regions of the housing portions,
  6. In which each of the stiffening bands has a profile that is asymmetric about a lateral axis of the body when viewed in plan.

The question of added matter boiled down to whether feature 6 was disclosed in the original application as filed.

At first instance, the judge concluded that the application as filed discussed asymmetry of the body as a whole, but did not refer to the individual stiffening bands as being asymmetrical. The judge also decided that the application included teaching that the PSBs can have a “hockey stick shape”, but concluded that the patent fell down on added matter because it claimed a wider class of PSBs, i.e. all asymmetric PSBs and not just hockey stick shaped ones.

During appeal, two key points were considered.

  • Did the application as filed disclose PSBs having an asymmetric profile about a lateral axis?
  • Nevertheless, does the patent fall down for added matter because it claims a wider class of asymmetric PSBs than disclosed in the application?

The Court of Appeal considered that although not expressly stated, it would be clear to the skilled reader that the PSBs were individually asymmetric about a lateral axis of the body. The decision concluded that the application contained clear and unambiguous disclosure of a class of PSBs which would fall within claim 1 of the granted patent because they would necessarily possess all of the features of the claim, including feature 6.

The decision went on to consider whether the patent nonetheless contravened the law on added matter because it claimed a wider class of asymmetric PSBs than were disclosed in the application. On this point, the court looked to a number of cases for guidance, including Texas Iron Works Inc’s Patent [2000]; A.C. Edwards Ltd v Acme Signs & Displays Ltd [1992]; and the EPO Technical Board of Appeal Decision: T0653/03 Toyota Jidosha KK.

The court concluded from these decisions that “the law does not prohibit the addition of claim features which state in more general terms that which is described in the specification. What the law prohibits is the disclosure of new information about the invention.” For example, in T0653/03, the replacement of the term “diesel engine” by “combustion engine” was considered to add matter because there was no disclosure that the invention was suitable for engines other than diesel engines. In A.C. Edwards, the court distinguished between what a claim covered and the matter that it disclosed. The court decided that although the claim covered certain variations, it did not contain disclosure of these. The Court of Appeal reasoned that in Texas Iron works and A.C. Edwards the claims and specification read together did not disclose any new technical information, despite there being a generalisation in the added claim feature.

The Court of Appeal concluded that upon considering the disclosure of the patent specification as a whole, the skilled person would understand that the patentee has drafted a claim that covers asymmetric PSBs generally. However, the patent as a whole does not disclose any PSB configurations which are not disclosed in the application as filed. The skilled person would understand from the granted patent, in the same way as from the application, that the PSBs disclosed are asymmetrical about the lateral axis. The skilled person would also understand that the PSBs are exemplified by the “hockey stick” shapes described in specific embodiments. The skilled person would not, therefore, learn any new information about the invention.

This decision gives a good indication of how the UK courts are assessing added matter. The decision is also interesting in perhaps indicating that the UK courts are approaching added matter a little more leniently than the EPO. For example, the Court of Appeal’s reasoning that “the law does not prohibit the addition of claim features which state in more general terms that which is described in the specification. What the law prohibits is the disclosure of new information about the invention.” strikes me as being more lenient than the EPO. The EPO tend to assess added matter by considering whether the amendment would lead to the skilled person, using common general knowledge, being presented with information that is not directly and unambiguously derivable from the application as filed. In practice, the EPO will often consider that an amendment generalising a feature will not meet this “directly and unambiguously derivable test”.

For advice on issues surrounding added matter during prosecution or after grant, please feel free to contact one of our patent attorneys.

This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.

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