Royalty payments shall be made by wire transfer in United States currency to a designated bank account of Sublicensor in the United States and shall be due forty-five (45) days after the close of each Reporting Period. Payment of royalties in whole or in part may be made in advance of such due date. In case no royalty is due for any given Reporting Period, Sublicensee shall so report to Sublicensor.  Sublicensee shall keep accurate records for a period of at least three (3) years in sufficient detail to enable the royalty payable hereunder to be determined and confirmed.