The CO is responsible for determining the need for progress payments and must consult the client and Legal Counsel regarding the nature of contract performance in relation to the specific purchase and payment terms stipulated in the contract. The CO must obtain monthly progress reports from the supplier, illustrating progress of the work as related to progress payments made. The CO may, when approving progress payment requests, rely on the supplier’s accounting system. However, postpayment reviews (including audits, when considered necessary) must be made periodically to determine the validity of progress payments already made and expected to be made. The CO will consult the client regarding the progress of contract performance when progress payments are made.