The following is a revised version of the notice on the opposition procedure before the EPO published in OJ EPO 2001, 148 ff. It reflects recent developments in opposition procedure that will take effect as from 1 July 2016.

1. The notice of opposition

Opponents are recommended to use Form 2300, irrespective of the chosen means of filing.

Notice of opposition may be filed in electronic form using the EPO Online Filing software (see OJ EPO 2015, A91) or using the new online filing service (CMS) provided on the EPO website (OJ EPO 2015, A27). However, it may not be filed using the EPO web-form filing service (OJ EPO 2014, A98). If documents are filed online, the EPO electronically acknowledges receipt within the submission session.

Notice of opposition may also be filed by fax or by post using Form 2300, available on the EPO’s website. As in the above-mentioned cases of electronic filing, no written confirmation is required. Written confirmation reproducing the contents of the fax must only be supplied at the invitation of the EPO (OJ EPO 2007, Special edition No. 3, A.3).

With the notice of opposition, opponents should file all relevant documents, even those available in the EPO documentation, translations of any documents not in an EPO official language and, wherever possible, a copy of any further evidence indicated in the notice.

The notice of opposition must contain an indication of the facts, evidence and arguments in support of the grounds for opposition (Rule 76(2)(c) EPC). The opponent must therefore give at least one ground for opposition under Article 100 EPC and indicate the facts, evidence and arguments adduced in support of the ground(s). If it fails to satisfy this requirement, the opposition is rejected as inadmissible (Rule 77(1) EPC).

The evidence indicated may also be submitted subsequently^[ * ]. If the opposition is admissible, the opponent will be invited to supply such evidence as a rule within two months. If the documents thus requested are neither enclosed nor filed within the time limit set, the opposition division may decide not to take into account any arguments based on them (Guidelines D-IV, 1.2.2.1(v)).

2. Multiple opponents

If several oppositions to a European patent are filed, they will be considered jointly. The notices of opposition and all further submissions made by individual parties will be communicated to all other parties.

3. Reply of the proprietor

After examination for admissibility or after expiry of the time limit set by the opposition division for remedying deficiencies noted in a communication under Rule 77(2) EPC, the patent proprietor is invited to file its observations and any amendments to the patent within four months (Rules 79(1), 132 EPC). The same applies after expiry of the time limit set for furnishing cited documents or evidence not already filed with the notice of opposition.

The patent proprietor should within the specified time limit submit a full response to the opposition(s), i.e. all the facts, evidence and arguments in support of its case. If necessary, it should submit amended documents to meet the grounds for opposition.

The observations and any amendments filed by the patent proprietor are immediately communicated to the opponent (Rule 79(3) EPC) for information.

At the same time, the opposition division will prepare the next action.

If the opposition division considers it necessary, it will dispatch a communication and invite the parties to reply within a specified time limit. In most cases however the opposition division will issue summons to oral proceedings.

4. Time limits

The normal period for replying to communications from the opposition division is four months for communications raising matters of substance and two months for other communications (Guidelines E-VII, 1.2).

Extensions of time limits are granted only in exceptional cases with duly substantiated requests.

5. Facts and evidence not submitted in due time

The opposition division may disregard facts or evidence which are not submitted in due time by the parties concerned (Article 114(2) EPC), unless they are of prima facie relevance, i.e. they would affect the outcome of the decision to be taken.

In order for the proceedings to progress expeditiously, parties should submit all facts, evidence and requests at the beginning of the procedure. Where this is not possible, the facts, evidence or requests must be submitted at the earliest opportunity. If relevant facts or evidence are submitted by a party only at a late stage of the proceedings without very good reason and if, as a consequence, the costs of oral proceedings or taking of evidence are incurred by another party, this may be taken into account in the apportionment of costs.

6. Examination by the EPO of its own motion

Examination of the opposition is confined to the parts of the patent contested by the opponent(s) and the grounds put forward by them. Exceptionally, the opposition division may in accordance with Article 114(1) EPC consider other grounds for opposition which, prima facie, in whole or in part would seem to prejudice the maintenance of the European patent.

The opposition division will only undertake a more extensive examination (Article 114(1) EPC) if facts come to its attention which clearly wholly or partially prejudice the maintenance of the patent (see Guidelines D-V, 2). However, opposition is not an opportunity for the EPO to undertake a complete re-examination of the patent of its own motion.

If the patent proprietor submits amended documents, the amended parts must be checked for compliance with all the requirements of the Convention. Regarding clarity, amended claims may be examined for compliance with the requirements of Article 84 EPC only to the extent that an amendment introduces non-compliance with that article (G 3/14).

If a sole opposition or all oppositions are withdrawn, the opposition proceedings may be continued by the EPO of its own motion. This is always the case when the examination necessary for the decision has already been concluded, or can be concluded without the participation of the opponent(s), and if it appears that the patent cannot be maintained unamended (see Guidelines D-VII, 5.3). It is also the case if the proprietor has itself submitted amendments (see Article 113(2) EPC).

7. Subsequent procedure

If oral proceedings are requested by one of the parties or considered expedient by the opposition division itself, a date for oral proceedings is fixed.

If the opposition division considers it necessary to seek further clarification of the facts or to hear one party’s observations on another party’s submissions before summoning to oral proceedings, the party concerned will be invited to comment on the submissions within a specified period (Guidelines D-VI, 3.1).

If no oral proceedings are to be held and if no further clarification of the facts is necessary, i.e. if the decision can be based on grounds on which the parties have had an opportunity to comment in writing (Article 113(1) EPC), the opposition will be decided on immediately.

8. Oral proceedings

The date on which the oral proceedings are to take place is specified in the summons. As a rule it will not be earlier than six months after dispatch of the summons. Requests to alter this date may only be considered in exceptional, duly substantiated cases (see notice in OJ EPO 2009, 68).

With the summons to oral proceedings, the parties also receive a communication setting out the issues which in the opposition division’s view must be discussed at the oral proceedings.

The annexed communication will also contain the opposition division’s provisional and non-binding opinion on the positions adopted by the parties and in particular on amendments filed by the proprietor of the patent (see Guidelines D-VI, 3.2, and E-II, 6), where applicable making suitable reference to certain parts of the file. The summons will also fix a final date for submitting observations and amendments (Rule 116 EPC). This date is normally set at two months before the oral proceedings.

The subject of the oral proceedings are the crucial issues listed in the annexed communication, but the parties are not confined to those issues alone, provided that their additional submissions are relevant.

In oral proceedings, the opposition division normally gives the floor first to the party raising an objection. Each party is given the opportunity to state its case and to reply to the other party. Where necessary, the opposition division asks the parties for clarification.

Oral proceedings are generally concluded by a decision based on the parties’ final submissions and requests. To this end, the representatives of the parties should come to the oral proceedings prepared to consider possible fall-back positions and armed with the authority to take a stand on behalf of their clients on any developments which may occur in the course of the proceedings.

If new facts or evidence (e.g. a new document) are submitted for the first time at the oral proceedings, they are to be regarded as late-filed (Rule 116 EPC) and will only be considered if they are of such prima facie relevance that the opposition division, in the exercise of its discretion, admits them into the proceedings under Article 114(2) EPC. In such cases, oral proceedings should be interrupted briefly to enable the other parties to study the new submission. If it is unreasonable to expect the other parties to be able to formulate an adequate response, the proceedings must be continued in writing.

At the end of the oral proceedings, after a brief adjournment for deliberation, the chairman normally pronounces the opposition division’s decision. A brief statement of grounds may also be given. The decision is notified to the parties in writing without delay (Rule 111(1) EPC).

If the opposition division’s interlocutory decision was based on documents which do not comply with Rule 49(8) EPC, i.e. which contain handwritten amendments, the opposition division will invite the proprietor in the communication under Rule 82(2) EPC to file a formally compliant version of the amended text (see OJ EPO 2016, A22).

The outcome of the oral proceedings will be published in the European Patent Register.

9. Minutes of oral proceedings

The minutes of the oral proceedings, where appropriate together with the decision, are sent to all the parties as soon as possible.

10. Closure of proceedings

The proceedings will in every case be concluded with a decision. The opposition division may decide to revoke the European patent, to reject the opposition or to maintain the patent in amended form (Article 101 EPC).

If the patent proprietor no longer wishes to maintain the patent, it can request that the patent be revoked. The patent is then revoked because no text approved by the proprietor is available (Article 113(2) EPC).

Revocation can also be expected if the proprietor informs the EPO that it renounces the patent in respect of all the designated contracting states.

The opposition division can also terminate the proceedings by means of a formal decision if the opposition is withdrawn (Rule 84(2) EPC). Similarly, the opposition division will close the proceedings if the European patent has been surrendered or has lapsed for all the designated states and the opponent does not request continuation of the opposition proceedings within the period specified in Rule 84(1) EPC.

11. Hearing of witnesses

Witnesses offered to give testimony (Rule 117 EPC) on a contentious issue will be heard if the contested issue is relevant for a decision on the maintenance of the opposed patent. This may be the case where a prior use is claimed and the witness offered was involved.

12. Costs

Each party generally bears its own costs. Under Article 104(1) and Rule 88 EPC, the costs may be otherwise apportioned "for reasons of equity". Reasons of equity will require a decision on the apportionment of costs when the costs are culpably incurred as a result of irresponsible or even malicious actions. Each party may of course defend its rights or interests by any legally admissible means within the framework of the opposition proceedings; it may, for example, request oral proceedings or the taking of evidence. Therefore the patent proprietor has to bear the costs involved in replying to a notice of opposition even if the opposition subsequently proves to be wholly unfounded.

If a party has exercised delaying tactics or conducted itself unreasonably, the opposition division may decide on a different apportionment of costs. Examples in which the opposition division may decide to apportion costs are given in Guidelines D-IX, 1.4.

13. Intervention of the assumed infringer

A third party may intervene in opposition proceedings, under the conditions stipulated in Article 105 EPC, as long as they have not been concluded (see Guidelines D-VII, 6). If the intervention is properly filed, it is treated as an opposition. This means that, regardless of the stage at which the intervener becomes a party to the proceedings, it enjoys essentially the same rights as any other party.

14. Accelerated processing of oppositions

In cases where an infringement action in respect of a European patent is pending before a national court of a contracting state, a party to the opposition proceedings may, at any time, request accelerated processing (OJ EPO 2008, 221).

However, the proceedings can only effectively be accelerated if the parties make their submissions promptly and in full, and strictly adhere to the time limits. Requests to extend time limits over and above the normal four-month period will only be granted in exceptional and duly substantiated cases.