Free tools · EP opposition deadline
When does the European opposition period end?
Anyone may oppose a European patent within nine months of the publication of the mention of its grant in the European Patent Bulletin (Article 99 EPC). Enter the publication date below for the last day. The period cannot be extended, and the opposition fee must be paid within it.
By patent number
One number, any format. Pick what you want to know about it, or ask for everything.
Free. Five lookups a day per visitor; fifteen with an email. The examiner's search log is read by a paid transcription, so it is limited to three new patents a day per visitor and twenty for everyone. A patent already read is always free and never counts. Resets at midnight UTC.
Every answer shown here, by email, with a link back. Also lifts your limit to fifteen lookups a day.
Deadline calculators
Dates in, dates out. The IPR one-year bar, the PTAB milestones, a contest's close in your own zone, the PCT national phase and the EP opposition window.
Date the complaint was served (35 U.S.C. §315(b)).
Date the IPR petition was filed.
The close as posted, Eastern Time.
Earliest priority date. 30 months for most offices; 31 for the EP and some others.
Date the mention of the EP grant was published. An opposition is due 9 months later (Art. 99 EPC).
Statutory and rule-based intervals, counted in calendar days; the PTAB lines are the usual milestones, and the Board's own scheduling order governs. Not legal advice. Feeds the invalidity search.
WO / PCT report reader
A WO number in; out: the international search report's citations with their X, Y and A categories and the claims each was aimed at, the earliest priority, the national-phase dates, and whether the US national phase has been entered.
International search report · EPO record
- X
- Y
- A
X: relevant alone. Y: relevant combined with another. A: background. Only the searching authority's own citations are listed, not the applicant's. National-phase limits vary by office; check the WIPO PCT time-limits table for the one you need.
Wayback date-prover
A URL in; out: the earliest archived capture of the page and its link, as a citable line for dating a manual, a datasheet or a product page. A capture proves the page existed by that date; it says nothing about when it was first published. Feeds the non-patent literature sweep.
From the Wayback Machine
About this tool
Opposition is centralised: one proceeding at the EPO can revoke or narrow the patent in every country where it was validated, which makes it far cheaper than national invalidity actions.
The opposition must set out its grounds and evidence within the nine months, so the prior-art search has to be done before the period ends, not after.
Questions
- Is the opposition period counted from the grant decision?
- From the date the mention of grant is published in the European Patent Bulletin, which is also the date the patent takes effect.
- Can the nine months be extended?
- No. Neither further processing nor re-establishment of rights is available to an opponent who misses it.