Protest

can be filed by an applicant if he does not agree with the request to pay an additional fee following a decision on lack of unity of invention taken during either the international search or the international preliminary examination (international phase of the PCT) (Articles 17(3)(a) and 34(3)(a), Rules 40.2 and 68.3 PCT, Articles 154(3) and 155(3) EPC).
  

Any additional search fees or additional preliminary examination fees requested by an International Authority may be paid under protest, that is, accompanied by a reasoned statement to the effect that the international application complies with the requirement of unity of invention or that the amount of the required additional fees is excessive.