The opposition procedure within the framework of the European Patent Convention (EPC) offers third parties the possibility to attack a European patent as a whole – that is, before it transforms into a bundle of national patents. After expiry of the opposition period, a party wishing to attack a European patent must launch an invalidation proceeding in every single member state of the EPC where the European patent has been validated. This, of course, is a time-consuming and costly procedure. Moreover, the result of such proceedings may well differ from country to country. The European opposition procedure is thus by far the most important tool for third parties wishing to attack a European patent.

The decisions taken by the Opposition Divisions and the Boards of Appeal of the European Patent Office (EPO) are known for being legally and technically well-founded, because of the high technical and legal education and knowledge of the members of those juridical panels. As a similar system is lacking in the US, for example, many of the big global players that apply for their patents at least in the most important economic regions of the world (Europe, US and Japan), tend to accept the decisions of the European Patent Office and make them the basis also for their handling of patent disputes worldwide.

It is certainly a further advantage of the European opposition procedure that, on an average basis, the costs are comparatively low – between about €50,000 ($78,000) and €100,000 ($154,000) – and that the average duration of the proceedings (two to three years for each instance) is reasonable.

High success rate

All these issues have contributed to the high popularity of the European opposition procedure. About 3,000 patents are opposed every year, amounting to about 5% of the total number of granted patents (see figure 1). Many of the cases are further pursued in the second instance, shown by the 2,000 or so appeal cases filed in 2006, with about two-thirds being appeals in opposition cases (see figure 2).

Figure 1: Examinations completed/patents opposed

Source: EPO Annual Report 2006

Figure 2: Technical appeals received/settled

Source: EPO Annual Report 2006

The popularity of the European opposition procedure is further enhanced by the encouraging figures regarding the success rate of oppositions (see figure 3). In about one-third of the cases, the patent is completely revoked. In another third, at least a reduction in scope of protection is achieved. For those that were unsuccessful in the first instance, the statistics indicate that it is worth the effort to file an appeal, because about 50 % of the first instance decisions are overturned by the Boards of Appeal (figure 4).

Figure 3: Decisions in opposite cases

Source: EPO Annual Report 2006

Figure 4: Boards of appeal: situation in 2006 (click to enlarge)

Source: EPO Annual Report 2006

An opposition can be based only on the grounds as given in Article 100a), 100b) and 100c) EPC. Article 100a) EPC includes several grounds, namely those laid down in Articles 52 to 57 EPC. The crucial ones are lack of novelty (Article 54 EPC) and lack of inventive step (Article 56 EPC). The ground of Article 100b) (corresponding closely to Article 83 EPC) is that the disclosure in the patent must be enough to enable a skilled person to carry out the invention. The requirement of Article 100c) (corresponding essentially to Article 123(2) EPC) prescribes that no subject matter must have been added to the content of the application as filed.