If the payer provides evidence to the EPO that, within the period for payment of a given fee, they took in an EPC contracting state one of the following steps:[Art. 7(3) RFees; Art. 7(4) RFees; ]
then they are considered to have observed the period for payment of the fee, even if the amount paid is received by the EPO after expiry of the period mentioned.
The EPO may request the person who made the payment to produce evidence, within a period to be specified by it, as to the date on which one of the conditions mentioned above was fulfilled in order for the period for payment of the fee to be considered observed.[]
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/a_x_6_2_1.htm
Date retrieved: 17 May 2021