8  Payment

8.1  The Authority shall pay the Contractor the agreed cost for carrying out or implementing any Authority Change:

(a)  which is a Low Value Change, in accordance with paragraph 5 (Payment) of Part 2 (Low Value Changes); or

(b)  which is a Medium Value Change or a High Value Change either by way of:

(i)  an adjustment to the Unitary Charge, by incorporating the Change in Project Costs in accordance with Schedule ♦ (Adjustment of Base Case); or

(ii)  subject to paragraph 8.2, within twenty (20) Business Days of receipt of an invoice submitted by the Contractor for the agreed amount.

provided that in the case of paragraph 8.1(b)(i) no adjustment of the Unitary Charge shall take place until the aggregate value of the adjustment required exceeds the sum of £[•] (indexed) or, once a year if the aggregate sum is not achieved in any Payment Year.

8.2  Where the Authority agrees to pay any Capital Expenditure incurred in carrying out a Change:

(a)  the Authority and Contractor shall agree:

(i)  a payment schedule in respect of the payment of the Capital Expenditure reflecting the amount and timing of the costs to be incurred by the Contractor in carrying out the Authority Change, to the extent borne by the Authority; and

(ii)  where payment for part of the Authority Change reflects the carrying out of, or specific progress towards, an element within the Authority Change, an objective means of providing evidence confirming that the part of the Authority Change corresponding to each occasion when payment is due under the payment schedule has been duly carried out,

and such payment schedule and evidence shall be determined in accordance with the Dispute Resolution Procedure in the event of the Authority and Contractor failing to agree as to its terms;

(b)  the Authority shall make a payment to the Contractor within twenty (20) Business Days of receipt by the Authority of invoices presented to the Authority (complete in all material respects) in accordance with the agreed payment schedule (as may be varied by agreement from time to time) accompanied by the relevant evidence (where applicable) that the relevant part of the Authority Change has been carried out; and

(c)  if payment is not made in accordance with paragraph 8.2(b), the Authority shall pay interest at the Prescribed Rate to the Contractor on the amount unpaid from the date twenty (20) Business Days after receipt of the relevant invoice until the date of payment.

8.3  Where, pursuant to paragraph 5.1, due diligence has been carried out by the Senior Lender, then the Authority shall reimburse the Contractor for the actual costs of the Senior Lender carrying out due diligence of a proposed Authority Change, provided that:

(a)  in the case of a Low Value Change, the Low Value Change Threshold has been exceeded; or

(b)  in the case of a Medium Value Change, the Medium Value Change Threshold has been exceeded; and

(c)  the sums due shall never exceed the lower of the cap set out in to paragraph 5.2 and the caps or fixed sum set out in the relevant Contractor Response

and, where the costs of the due diligence have not been included in the Change in Project Costs, the Authority shall pay such costs within twenty (20) Business Days of receipt of an invoice submitted by the Contractor for the agreed amount.

8.4  Notwithstanding any other provision of this Change Protocol:

(a)  the provisions of clause 59 (Change of Law) shall apply to the payment of any costs incurred or any savings made in carrying out or implementing any Change which is required as a result of a Qualifying Change in Law; and

(b)  the provisions of clause 39 (Best Value) shall apply to the payment of any costs incurred or any savings made in carrying out or implementing any Change which is required as a result of a CAA Change.