A more thorough explanation:

A through bill of lading is a document used in shipping that covers the transportation of goods from the point of origin to the final destination, even if multiple carriers are involved in the process. It is similar to a regular bill of lading, but it includes all the carriers involved in the shipment.

Let's say a company in New York wants to ship goods to a customer in Los Angeles. The company hires a trucking company to transport the goods from their warehouse to a port in New York. From there, the goods are loaded onto a ship and transported to a port in Long Beach, California. Finally, another trucking company picks up the goods from the port and delivers them to the customer in Los Angeles.

In this scenario, a through bill of lading would be used to cover the entire journey of the goods, from New York to Los Angeles, even though multiple carriers were involved.

A through rate is the total shipping cost when two or more carriers are involved in transporting goods. The carriers agree in advance on a through rate, which is typically lower than the sum of the separate rates.

Using the same scenario as before, let's say the trucking company charges $500 to transport the goods from New York to the port, and the second trucking company charges $300 to deliver the goods from the port to the customer in Los Angeles. If the companies charged separate rates, the total cost would be $800. However, if they agree on a through rate in advance, they may charge only $700, which is a discount for the customer.

The example illustrates how a through rate can be beneficial for customers who need to transport goods using multiple carriers. By agreeing on a through rate, the carriers can offer a lower price, which can save the customer money.