41 CFR 102-118.135: -118.135 Audit choices.

Agencies may perform a prepayment audit, post payment audit, or both.

(a) Pre-payment audits focus on preventing overpayments by identifying invoice errors before payment. They help prevent overspending, ensure payments align with contracts, reduce administrative burdens, and strengthen carrier relationships by promoting transparency and accuracy.

(b) Post-payment audits, on the other hand, serve as a second line of defense after payments are made. They recover overcharges, uncover systemic issues and trends, and provide valuable data for negotiating better carrier contracts and optimizing freight processes through continuous improvement.

(c) Jointly, these audits form a complementary strategy: pre-payment audits minimize upfront errors and spending, while post-payment audits recover missed costs and drive long-term optimization. Combining both approaches enhances overall freight cost control and operational efficiency.