Opposition procedure before the European Patent Office

Purpose, framework, and available grounds

The purpose of the opposition proceedings is to give opponents, such as competitors, the opportunity to challenge the validity of a granted European patent. Opponents may also challenge only some of the claims of the European patent (although this is in practice rather unusual), therefore limiting the framework of the opposition to the challenged claims.

However, an opposition can only be based on a limited number of grounds (i.e., objections) specified in the European Patent Convention, namely the grounds listed in Article 100 EPC. An opposition can be based on the grounds that the subject-matter of the patent is not patentable (Article 100(a) EPC, for instance because the claimed invention is not new or not inventive), on the ground that the invention is insufficiently disclosed to allow a person skilled in the art to carry it out (Article 100(b) EPC), or on the ground that the content of the patent extends beyond the content of the application as filed –"or, if the patent was granted on a divisional application or on a new application filed under Article 61 EPC, beyond the content of the earlier application as filed"– (Article 100(c) EPC). An opposition can for instance not be validly based on the grounds that the invention lacks unity (Article 82 EPC) or that the right to the European patent does not belong to the proprietor of the patent (Article 60(1) EPC).

Filing and admissibility

Before starting the substantive examination of the opposition, the Opposition Division examines whether the opposition must be considered as filed ("Is there an opposition?") and whether it is admissible ("Is the opposition admissible?"). The Opposition Division may find that the opposition is not deemed to have been filed, for instance because the opposition fee has not been paid within the nine-month opposition period, because the notice of opposition is not signed or because the notice is not in an accepted language.

In order for an opposition to be admissible it must meet the provisions of

In addition, an opposition is also rejected as inadmissible if it fails to meet the requirements of Rule 76(2)(a), (b) and (d) EPC after the opponent was invited to remedy to these failures within a given time limit. If the opposition is not admissible, the opposition is rejected under Rule 77(1) or (2) EPC.

Inadmissible oppositions and oppositions which are deemed not to have been filed are not substantively examined (no examination on the merits). An opposition can only be rejected as inadmissible if the opposition has been first deemed to have been filed, and, if it is deemed to have been filed, the opposition exists, even if later the opposition is rejected as inadmissible. If an opposition is deemed not to have been filed, an already paid opposition fee is refunded. In contrast, if an opposition is rejected as inadmissible, an already paid opposition fee is not refunded.

Straw man

An opposition may be filed by a straw man to hide the identity of the party actually interested in having the patent revoked. A strawman is "a party acting on behalf of another person." In 1999, the Enlarged Board of Appeal held that the use of a straw man did not render the opposition inadmissible unless "the involvement of the opponent is to be regarded as circumventing the law by abuse of process."

Substantive examination

If the opposition is admissible, the grounds for opposition are examined as to their merits. The patent proprietor has also the opportunity to reply to the grounds of opposition developed by the opponent. Arguments and, to a certain extent, amendments may be filed in reply by the patent proprietor.

In view of the grounds of opposition, and in view for instance of a prior art document introduced into the proceedings by the opponent, the patent proprietor may amend the patent, i.e. the description, claims and drawings of the patent, although amendments may not be filed of right at any stage during the opposition proceedings. The patent proprietor is master of its own patent in that the decision to amend or not, and how to amend the patent, is a decision of the patent proprietor alone (although the Opposition Division or the opponent may apply pressure to have amendments made). The patent, however, may not be amended in such a manner that the amendment would lead to an extension of the protection conferred by the patent.

If amendments are made to the patent during the opposition proceedings, the patent (and the invention to which it relates) must meet the requirements of the EPC. These requirements notably include the requirements of support in the description and clarity (Article 84 EPC), even though those are not listed as grounds of opposition in Article 100 EPC. However, the requirements to be met by the amended patent do not include the requirement of unity of invention (because divisionals cannot be filed after grant).

During the opposition, oral proceedings may take place at the request of the EPO or at the request of any party to the proceedings, i.e. the patentee or an opponent. The oral proceedings are held before the Opposition Division itself. They are held in Munich, the Hague or Berlin, and are public unless very particular circumstances apply. This contrasts with oral proceedings held before an Examining Division, which are not public. The list of public oral proceedings in opposition before the EPO is available on its web site. The right to oral proceedings is a specific and codified part of the procedural right to be heard. A decision is often taken at the end of the oral proceedings.

Outcome and effects of the opposition

The opposition proceedings may have one of three outcomes:

The opposition has effect on all designated states in the European patent. Decisions by Opposition Divisions, like any other final decisions of first instance divisions, are appealable.

A decision of the EPO to revoke a European patent is final (when the opportunity to appeal before the EPO is exhausted), which makes the opposition proceedings at the EPO especially attractive for opponents. In contrast, a decision of the EPO not to revoke a European patent (the decision instead maintaining the patent as granted or in an amended form) leaves the way open for revocation by the national court. The EPO decision does not create an estoppel precluding a subsequent challenge by an unsuccessful opponent at the national level (at least before the English courts). The validity of a European patent can be scrutinised both at the national level, before a national court, and at the international level, before the European Patent Office during opposition. The same is not true for infringement proceedings, upon which national courts exercise exclusive jurisdiction.

Apportionment and fixing of costs

Each party to the opposition proceedings normally bears the costs it has incurred, unless the Opposition Division (or, in appeal proceedings, the Board of Appeal under Rule 100(1) EPC), for reasons of equity, orders a different apportionment of costs. For example, in case T 1306/05, a highly relevant document had been lately filed, without any valid justification, by the opponent during the oral proceedings before the Board of Appeal, thus rendering useless both the oral proceedings and the patent proprietor preparation thereto. A different apportionment of costs has been ordered by the Board of Appeal. The patent proprietor has requested, under Rule 88(2) EPC and Rule 100 EPC, about €26,000 to be paid by the opponent.

During first instance proceedings, a decision on apportionment of costs forms part of the main decision of the Opposition Division. The main decision however only deals with the obligation on the party or parties concerned to bear costs (apportionment), whereas the actual amounts to be paid by one party to another are dealt with in another decision, namely a decision on the award (fixing) of costs. A decision on the award of costs is taken only after a decision apportioning the costs has been taken and if a request is submitted to that effect. When a Board of Appeal has to rule on an apportionment of costs, both the apportionment of costs and the fixing of costs to be apportioned are dealt with in a single decision.

Transfer of opponent status

The opponent status cannot be freely transferred. As far as legal persons are concerned, the opposition can only be transferred or assigned to a third party together with the business assets belonging to a company, i.e. its economic activity, and more precisely the assets in the interests of which the opposition was filed. However, the status of an opponent passes to, i.e. is transmitted to, the opponent's universal successor in law in the case of a universal succession, such as for example in the case of a merger of two companies.

Intervention under Article 105 EPC

Under Article 105 EPC, any third party may intervene in ongoing opposition proceedings after the 9-month opposition period has expired, if the third party proves that "(a) proceedings for infringement of the same patent have been instituted against him, or (b) following a request of the proprietor of the patent to cease alleged infringement, the third party has instituted proceedings for a ruling that he is not infringing the patent." In other words, a third party may intervene "if faced with an infringement action or allegation of infringement (...) instituted in a national jurisdiction under national law."

The admissibility of an intervention is subject to conditions. The so-called notice of intervention must notably be filed within three months of the date on which proceedings referred to in Article 105 are instituted. An admissible intervention is treated as an opposition. If the intervention is admissible, the intervener becomes party to the opposition proceedings.

The possibility to intervene not only exists during pending opposition proceedings before an Opposition Division (i.e., during the first instance proceedings), but also during subsequent pending appeal proceedings before a Board of Appeal (i.e., during the second instance proceedings).

Observations by third parties under Article 115 EPC

Independently from the possibility to intervene in opposition proceedings (and then to become party to the proceedings), anyone may also file observations under Article 115 EPC. After publication of a European patent application, and a fortiori after grant of a European patent, anyone may file observations regarding the patentability of the invention which is the subject of the application (during examination proceedings) or patent (during opposition proceedings). In contrast to an intervener however, a person filing observations during opposition proceedings does not become party to the proceedings. This notably means that such person does not acquire the "bundle of procedural rights" created "in respect of the opponent", such as the right to be heard before any decision is taken. Observations by third parties, which must be filed in writing, may be filed by post or online. According to Board of Appeal 3.3.08, the observations have to be signed "in order to allow an identification of the third party" and, unless "adopted by a party to the proceedings as its own" or by the competent organ of the EPO of its own motion, "anonymous third party observations are to be disregarded altogether."

Statistics, costs and duration

Overall, about 5.5-6% of the European patents granted by the European Patent Office are opposed. Of those, over the course of 1980-2005, about 1/3 were revoked, 1/3 were maintained in an amended form, which generally means "reduced in scope", and 1/3 were maintained as granted, that is, the opposition was rejected. The same figures were cited in 2013. The opposition rate (i.e. the number of oppositions filed per 100 granted patents) before the EPO is consistently higher in the closest available proxy for the pharmaceutical sector than it is in organic chemistry and in all sectors (overall EPO average). The success rate depends however on the technical area (i.e., on the IPC classes).

The main reasons for revocation of a patent in opposition are a lack of inventive step (43%), a lack of novelty (22%) and an extension beyond the content of the application as filed (11%).

Filing an opposition before the EPO is reportedly relatively affordable, "as the cost varies between €6000 and €50,000 (including patent lawyers’ fees)" (as of 2009). In contrast, the costs for litigating a European patent can be much higher ("For example, in Germany the total litigation costs can be as high as €2 million with €10 million at stake"). An opposition case is reported to take on average three years to be handled by the EPO.

Parallel national proceedings

The "possibility of parallel validity proceedings in national courts and in the EPO is inherent in the legal arrangements in the EPC under which the EPO was established". If a third party files an opposition to a European patent with the EPO and also, in parallel, initiates a revocation action (also called "nullity action" or "validity proceedings") against the same patent before a national court, the national court (at least in England) may exercise its discretion to either

The rules and practice differ from country to country in that respect. "For example, as of 2008, Belgium and France will stay the main proceeding until a final decision has been reached by the EPO whereas in Germany, Italy, the Netherlands and in the United Kingdom such a stay is not automatic and in most cases the courts will continue the proceedings notwithstanding the opposition. ... However, in Germany national nullity proceedings cannot be started before the Federal Patent Court until the EPO opposition proceedings have been concluded or the opposition period has expired."

Composition of an Opposition Division

According to Article 19(2) EPC, "[a]n Opposition Division shall consist of three technically qualified examiners, at least two of whom shall not have taken part in the proceedings for grant of the patent to which the opposition relates. An examiner who has taken part in the proceedings for the grant of the European patent may not be the Chairman." Violations of Article 19(2) EPC are considered to be substantial procedural violations. If an Opposition Division considers it necessary in a particular case, the Opposition Division may be enlarged by the addition of a legally qualified examiner (who cannot "have taken part in the proceedings for grant of the patent").