Opposition proceeding

An opposition proceeding is an administrative process available under the patent and trademark law of most jurisdictions which allows third parties to dispute the validity of a granted patent or trademark.

Patents

In Europe, third parties may dispute the validity of a granted European patent by filing a post-grant opposition under the European Patent Convention (EPC).

In Germany, third parties may dispute the validity of a pending German patent application under German patent law.

Under United States patent law, an opposition proceeding is called a reexamination.

In Japanese patent law, opposition procedure after an examiner's decision to grant a patent was abandoned in 2003; trial for invalidation serves as the alternative.

Trademarks

In the case of trademarks, third parties may use opposition proceedings to "oppose" the acceptance of a trademark application after it has been accepted and published for opposition purposes. If an opposition is defeated the trademark will proceed to registration. Some jurisdictions operate a "post-grant" opposition system, whereby opposition is not possible until after registration (e.g. Japan).

See also

• Opposition procedure before the European Patent Office
• Patent infringement
• Patent watch
• Patentability
• Prior art
• Reexamination