The one thing that these comments leave out is the circumstances that lead to rebilling. Customers and even other brokers will often give inaccurate information such as product, weight, NMFC, class, piece count etc. when they request an initial quote. The carrier will reweigh which often leads to hight freight prices. When the broker gives the initial quote, there should be a clause that reads something along the lines of "this is a quote based on the information provided." This protects the broker. If the broker books a shipment based on the information the customer provided, and upon inspection by the carrier something has changed such as product, weight, piece count, etc, it's perfectly acceptable for the customer to pay as they requested a rate quote for a shipment that was not accurately described. Of course when a shipment has higher freight prices, the broker should be able to provide carrier documentation as to why the charges occured.