Opposition procedure

After a 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. For example, they might consider the invention to lack novelty or inventive step. Notice of opposition must be filed within nine months of the grant being mentioned in the European Patent Bulletin.

The opposition procedure is made up of the following steps:

1. Setting up the opposition division

Oppositions are considered by an opposition division. The opposition division normally consists of three experienced examiners, one of whom may have worked on the application in the examination phase. Usually, one of them takes the lead.

2. Examining the notice of opposition

When the EPO receives notice of opposition, the examining division communicates it to the patent's proprietor and checks that the reasons for the opposition are admissible. Opposition may be filed for the following reasons:

  • The subject-matter of one or more of the claims is not new or inventive.
  • The patent does not disclose the invention clearly and completely enough for it to be carried out by a person skilled in the art.
  • The subject-matter of the patent extends beyond the content of the application as filed.

Notice of opposition
: contains the opponent's contact details and those of their representative if they have one, details of the European patent being opposed and a statement on the extent of the opposition and the reasons for it.

3. Examining the opposition

The opposition division examines whether the reasons for opposition mean that the patent should not have been granted as it was. If necessary, it invites the parties to make observations on its or other parties' communications by a specific deadline. During this round of communication, the patent's proprietor can amend the description, claims and drawings.

4. Holding oral proceedings

Any of the parties can request oral proceedings. Oral proceedings are the norm in the opposition procedure.

5. Taking a decision and concluding the procedure

At the end of the opposition procedure, the opposition division takes one of the following decisions:

  • It revokes the patent.
  • It maintains the patent.
  • It maintains the patent, but with amendments.

The opposition division's work then ends.

However, within two months, its decision can be appealed. Appeals are handled by the independent Boards of Appeal.

Boards of Appeal
: these consist of the technical boards of appeal, the Legal Board of Appeal, the Enlarged Board of Appeal and the Disciplinary Board of Appeal.