The supplementary search fee is collected by the IB for the benefit of the EPO as Supplementary International Searching Authority (SISA/EP) and its amount is fixed by the EPO. It is to be paid within one month from the date of receipt of the supplementary search request (Form PCT/IB/375). The amount payable is the amount applicable on the date of payment.[Rule 45bis.3; Art. 2(1) RFees; OJ EPO 2018, A4; ]