The protest fee is paid for the benefit of the ISA/EP and its amount is fixed by the EPO. It is to be paid within one month from the date of the invitation to pay additional fees after the finding of lack of unity (Form PCT/ISA/206, see GL/PCT‑EPO B‑VII, 6.3). The amount payable is the amount applicable on the date of payment.[Rule 40.2(e); ]