Article 65⁵⁵, ⁵⁶
Translation of the European patent

(1) Any Contracting State may, if the European patent as granted, amended or limited by the European Patent Office is not drawn up in one of its official languages, prescribe that the proprietor of the patent shall supply to its central industrial property office a translation of the patent as granted, amended or limited in one of its official languages at his option or, where that State has prescribed the use of one specific official language, in that language. The period for supplying the translation shall end three months after the date on which the mention of the grant, maintenance in amended form or limitation of the European patent is published in the European Patent Bulletin, unless the State concerned prescribes a longer period. 

(2) Any Contracting State which has adopted provisions pursuant to paragraph 1 may prescribe that the proprietor of the patent must pay all or part of the costs of publication of such translation within a period laid down by that State.

(3) Any Contracting State may prescribe that in the event of failure to observe the provisions adopted in accordance with paragraphs 1 and 2, the European patent shall be deemed to be void ab initio in that State.