19.5.5.1 The Contract must specify what happens if the Contractor is able to provide the Service earlier than the Planned Service Commencement Date. The Authority should not be obliged to make any payment of the Unitary Charge before the Planned Service Commencement Date unless it has agreed in the Contract to accept earlier Service Commencement (see Section 8.6 (Bonus Payments for Early Service Commencement)). If early commencement is practical and agreed, then the Contract should also provide for adequate notice to be given to the Authority of a possible early Service Commencement Date so that the Authority can make all necessary preparations for earlier Service Commencement.