4.1.5 Date of filing 

The date of filing accorded to the application is the date the application meets the requirements of Rule 40 and is either:

(i)the date of receipt at the EPO or competent national authority; or 

(ii)the date, not later than the two-month period referred to in Rule 55, on which the applicant rectifies any deficiencies. In the latter case, the applicant is informed of the date of filing accorded to the application.

Case (ii) is subject to one exception. Where the application is filed by reference to a previously filed application and the applicant fails to file the certified copy of the previously filed application within two months of the filing date as required by Rule 40(3), an invitation is sent to the applicant to file it within a period of two months from a communication according to Rule 55. If the applicant files the certified copy within this two-month period, the application maintains its original date of filing, provided that all other requirements for acquiring a date of filing have been met.

The date of filing may also change in cases where the applicant inserts missing parts of the description or missing drawings under Rule 56 (see A‑II, 5) or corrects erroneously filed parts under Rule 56a (see A‑II, 6) after the date of filing (see A‑II, 5).