Rule 155
Filing and transmission of the request for conversion

(1) The request for conversion referred to in Article 135, paragraph 1(a) or (b), shall be filed within three months of the withdrawal of the European patent application, or of the communication that the application is deemed to be withdrawn, or of the decision refusing the application or revoking the European patent. The effect of the European patent application under Article 66 shall lapse if the request is not filed in due time.

(2) When transmitting the request for conversion to the central industrial property offices of the Contracting States specified in the request, the central industrial property office concerned or the European Patent Office shall attach to the request a copy of the file relating to the European patent application or European patent. 

(3)¹⁹⁹ Article 135, paragraph 4, shall apply if the request for conversion referred to in Article 135, paragraphs 1(a) and Article 135, paragraphs (2), is not transmitted before the expiry of a period of twenty months from the date of filing or, if priority has been claimed, the date of priority.