Normally, at the European Patent Office (EPO) a post-grant opposition can be filed within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin (Article 99(1) EPC). After this deadline, the European patent splits into a bundle of national rights, and each national right must be challenged for validity separately. There is therefore a clear benefit to filing an opposition before this deadline expires.

In the light of the COVID-19 situation, the focus has rightly been on how patent applicants can continue to meet deadlines and pay necessary fees. To this end, the EPO has provided that periods which would have expired on or after 15 March 2020 are extended to 2 June 2020. Please do check with your patent attorney before relying upon this extension, as it does not necessarily apply to all deadlines.

However, one period which this extension does apply to, and that may have been overlooked is the nine month period for filing an opposition. If the publication of the mention of grant of a European patent was between 15 June 2019 and 1 September 2019, the deadline for filing the opposition has been effectively extended until 2 June 2020.

If the European patent in question is your competitor's, this is excellent news as you have extra time to prepare and file an opposition, even if the deadline initially appeared missed. Although with under two weeks remaining (unless the EPO extends the deadline further), I suggest you speak to your patent attorney immediately! On the flip side, if you are the patent proprietor you could have additional months of uncertainty. This may mean that you want to hold back on any action against a potential infringer until the European patent can no longer be opposed.