After the European patent has been granted, it may be opposed by third parties – usually the applicant’s competitors – if they believe that it should not have been granted. This could be on the grounds, for example, that the invention lacks novelty or does not involve an inventive step. Notice of opposition can only be filed within nine months of the grant being mentioned in the European Patent Bulletin.
The opposition division normally consists of three experienced examiners, one of whom may have been involved in the substantive examination phase. One member of the division usually takes the lead in the opposition procedure.
When the EPO receives the notice of opposition, the examiner communicates it to the proprietor and checks that the grounds for opposition cited in the notice are admissible. Oppositions may be filed on the following grounds:
Notice of opposition: contains the opponent's contact details, details of the European patent that is being opposed, a statement on the extent and grounds of the opposition and contact details for the opponent's representative.
The opposition division examines whether the grounds for opposition prejudice the maintenance of the European patent. If necessary, the examiner invites the parties to file observations on its or other parties' communications within a specific period. During this round of communication, the patent holder can amend the description, claims and drawings.
Any of the parties, including the EPO examiners, can request oral proceedings, and most of the time they are set.
The conclusion of the oral proceedings should be one of these options:
The examiner's involvement ends after the opposition phase, although appeals can be filed against their decisions within two months of the date of notification. Appeals are dealt with by the independent boards of appeal.
Boards of appeal: there are currently 24 technical boards of appeal, plus the Legal Board of Appeal, the Enlarged Board of Appeal and the Disciplinary Board of Appeal.