The carrier is a company or individual who picks up and delivers your vehicle. They are generally not the company that you book your transport with. The broker is the company that you call to arrange your transport with the carrier for you. The broker's responsibilities include, but are not limited to:
To put it simply, a transport broker has a large quantity of drivers all over the country at his disposal to choose from and a carrier has only one to three drivers who are available to go to certain areas of the country per week. A broker does charge a small fee but your car will get moved much quicker. One problem that may arise is that some brokers do not have contracts with these carriers (owner-operators) and/or keep their insurance certificates in their offices. We do both and used to be carriers.
The main difference between auto transport brokers and auto transporters is that the latter own and manage their own trucks, while brokers typically do not own any vehicles. Their role is to act on your behalf, and quickly find a carrier in your local area that is able and willing to transport your vehicle as per your requirements.