I am a broker that arranged for a truck to pick up a load in Tremonton, UT and deliver to Norwalk, CA. The customer had the hired truck driver sign a load conformation with the incorrect rate and now the customer is refusing to pay the total invoice. I spoke with Elizabeth Walker with Levelset and she wasn't sure if I could lien this job site because it is for a freight charge. She has advised me to contact you to see if this is something that we can lien the job site for.
If the load was for contruction material delivered to CA, you would want to speak with a CA attorney to see if the CA lien laws would allow you to lien the site in Norwalk CA. Utah lien laws would not let you lien the pickup site in Utah.
Regarding the broker issue, you should review the specifics with a transportation attorney. Brokers typically have a broker-shipper contract with customers and a separate broker-carrier contract with carriers. Both should work to protect brokers from interference, collusion, or other issues between the shipper and carrier. Even in the absense of a formal written broker-shipper contract, when a broker arranges a load with a shipper, the shipper generally cannot change the terms of that arrangement via the carrier. As with any contract, both the original parties to the contract must agree on changes.