Periodic Services Charges. 8.5.1. You will incur Service Charges from the time any part of a Service is used or received except in the case of Services subject to a periodic Service Charge, in which case you will incur Service Charges from the date the Service is made available for use. We will usually ask you to pay the Service Charges in advance and your first invoice will include both one month’s Service Charge in advance and a Service Charge for a part month’s Service Charge from the Contract Commencement Date up to the beginning of the first complete month, where appropriate, and then monthly in advance thereafter.