The EPO first examines whether a patent application satisfies the requirements for the accordance of a date of filing in accordance with the Implementing Regulations (Art. 80 EPC, Art. 90(1) EPC and R. 40 EPC). Only if an application is accorded a date of filing is the examination as to formal requirements commenced (Art. 90(3) EPC).
Source: http://www.epo.org/law-practice/legal-texts/html/caselaw/2019/e/clr_iv_a_1.htm
Date retrieved: 17 May 2021