In the case of Article 17, paragraph 3(a) PCT, an additional international search fee shall be paid for each further invention for which an international search is to be carried out.
In the case of Article 34, paragraph 3(a) PCT, an additional fee for international preliminary examination shall be paid for each further invention for which the international preliminary examination is to be carried out.
Where an additional fee has been paid under protest, the European Patent Office shall examine the protest in accordance with Rule 40.2(c) PCT to Rule 40.2(e) PCT or Rule 68.3(c) PCT to Rule 68.3(e) PCT, subject to payment of the prescribed protest fee. Further details concerning the procedure shall be determined by the President of the European Patent Office.
See decision of the President of the EPO of 09.06.2015 providing for review panels for the implementation of the protest and review procedures under the PCT (OJ EPO 2015, A59) and notice from the EPO of 24.03.2010 concerning the protest and review procedures under the PCT (OJ EPO 2010, 322).