Freight pay is a service that allows you to pay your transportation bills online. To you, that might mean enlisting the help of your logistics or transportation manager to gather all of your numerous carrier invoices, and then delegating the chore of processing each payment through a direct clearing house or cutting individual checks to your accounting staff. Freight payment is a set of procedures that can be compared to an accounts payable service for transportation invoices in general. In order to receive, process, and pay invoices, freight payment services providers, such as a 3PL, function as an intermediary between the shipper and the carrier. Freight audits are an important part of cost control in the supply chain.