HomeInsightsHigh Court finds that reliance on doctrine of equivalence must be expressly pleaded in patent disputes


In a pre-trial review in a patent case concerning a European Patent (UK) entitled “Telecommunication and Multimedia Management Method and Apparatus” belonging to Voxer IP LLC, Lord Justice Birss had to decide whether reliance on the doctrine of equivalents has to be expressly pleaded. The point has been in doubt since the law was changed by Actavis v Eli Lilly [2017] UKSC 48. In short, Birss LJ said that, yes, the point must be expressly pleaded.

In these patent infringement proceedings, Voxer contends that certain functionality offered by Facebook Ireland Ltd, known as Facebook Live and Instagram Live, infringes its patent. Facebook denies infringement and contends that the patent is invalid. The matter, which started as a claim for revocation by Facebook following infringement claims against Facebook brought by Voxer in Germany and the USA, is proceeding under the Shorter Trials Scheme (STS).

In the Particulars of Infringement, served with Voxer’s Defence and Counterclaim, Voxer identified the alleged infringements and the patent claims infringed. However, it did not particularise how the claims covered the products or processes alleged to infringe. Voxer then produced a Statement of Case on Infringement, which contained claim charts identifying the claim integers of each claim and where those features were found in the alleged infringement. However, Voxer made no reference in either document as to whether infringement was advanced on the doctrine of equivalents (Actavis).

Voxer then served a draft amended Statement of Case on Infringement setting out infringement based on the doctrine of equivalents. Voxer’s new case is that even if the operation of the alleged infringing method falls outside claim 1 in relation to the particular feature on a normal interpretation of that feature, its operation is equivalent to the operation of the relevant aspect of claim 1. The document then briefly states what the inventive concept is that will be relied on and puts the case on the three limbs of the Actavis test.


Facebook objected to Voxer being permitted to run the new point on various grounds including on the basis that a case under the doctrine of equivalents should be pleaded, with proper identification of the inventive concept. Birss LJ agreed. CPR Part 63 rule 63.6 provides that a Statement of Case in a patent case must set out the matters in Practice Direction 63. PD63 paragraph 4.1 sets out matters that must be pleaded in the Particulars of Infringement. The fact that equivalents are not mentioned in paragraph 4.1 does not mean that it need not be mentioned at all. These provisions all function in an overall context governed by CPR Part 16 about Statements of Case in general. Rule 16.4(1)(a) provides that Particulars of Claim must include “a concise statement of the facts on which the claimant relies”. A case based on the doctrine of equivalents inevitably involves an assertion or assertions of fact that are distinct from the general questions of fact arising in relation to infringement on a normal construction. The first and the second Actavis questions necessarily include such distinct issues of fact. Therefore, by the application of the general rule 16.4, equivalence to a particular claim feature must be pleaded.

Birss LJ also said that the point must be pleaded so that the alleged infringer knows the case it has to meet. The patentee must state in terms that equivalence is relied on and do so by reference to the particular feature of the claim. As for when this should be done, Birss LJ suggested that the time when claim charts or a Statement of Case on Infringement is produced would be an appropriate time.

Birss LJ concluded that the minimum required to satisfy CPR rule 16.4 is for the Particulars of Infringement to contain a statement, by reference to each relevant claim feature (and claim), that equivalence is relied on. If a patentee makes such an assertion that it cannot later explain in a claim chart or Statement of Case then no doubt the assertion will be struck out.

Accordingly, at the hearing, Birss LJ accepted Facebook’s arguments on the pleading point of principle, but nevertheless went on to permit Voxer to run the new argument on case management grounds.  The written judgment sets out his reasons on the point of principle (only), because litigators have been in doubt on the point since the Actavis judgment.  (Facebook Ireland Ltd v Voxer IP LLC [2021] EWHC 657 (Pat) — to read the judgment in full, click here).