Within nine months from the publication of the mention of the grant of the European patent, notice of opposition has to be given to the EPO in Munich, The Hague or Berlin.[Art. 99(1); ]
For expiry of the time limit see E‑VIII, 1.4. Re-establishment of rights in respect of unobserved time limits for opposition is not possible in the case of an opponent (see, however, E‑VIII, 3.1.2).
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/d_iii_1.htm
Date retrieved: 17 May 2021