PCT Receiving Office Guidelines
Chapter XI: Fees
Application of Moneys Received
266. The receiving Office applies the moneys received according to the instructions received from the applicant as outlined in Section 321 and Rule 16bis.1(c). Where the moneys received by the receiving Office are not sufficient to cover the fees due, and the receiving Office has not received instructions from the applicant as to the fees to which it shall apply the moneys, the receiving Office shall apply the moneys received in payment, successively, of the fees in the following order and to the extent that they are due and unpaid:
(i) the transmittal fee;
(ii) the international filing fee;
(iii) the search fee.