1.1 Calculate the Monthly Service Payment payable in respect of a Contract Month "n" using the following formula:

where:
MSP is the Monthly Service Payment for the Contract Month n;
ASPn is the Annual Service Payment for the Contract Year in which Contract Month n occurs, calculated in accordance with paragraph 1.2 below;
ΣD is the sum of Deductions in respect of performance of the Services during the Contract Month that was 2 months prior to Contract Month n as shown in the Monthly Service Report for that Contract Month and calculated in accordance with the provisions set out in Section 3 (Deductions from Monthly Service Payments) of this Schedule Part 14 (Payment Mechanism);
PTC means any Pass Through Costs due for which supporting uncontested invoices from Sub-hubco's suppliers are available;
1.2 In the Contract Month in which the Payment Commencement Date falls, unless the Payment Commencement Date is the first day of that Contract Month, and in the last Contract Month of the Project Term, unless the last day of the Project Term is the last day of that Contract Month, adjust ASPn for the purposes of paragraph 1.1 above pro rata to reflect the actual number of days in the relevant Contract Month from and including the Payment Commencement Date (for the first month) and (for the last month) up to and including the last day of the Project Term (for the last month).